King Boo

"Seriously, though, who would actually believe that mansions get given away in contests?! Talk about stupid! What do they feed you Mario brothers anyway... gullible soup?"

- King Boo

King Boo (Japanese: キングテレサ King Teresa) is the leader of the Boos and the main antagonist of the game Luigi's Mansion. He is also an ally of Bowser, King of the Koopas, and has aided the Koopa leader in his various schemes. He first appeared as Luigi's nemesis, and is more than capable of devising and enacting villainous plans by himself, including his capture and imprisonment of the hero Mario. Although not the biggest Boo in the Mushroom World, King Boo has abilities that far surpass that of the average ghost, and wields a number of impressive magical abilities, including the ability to materialize objects out of thin air. King Boo's magical power is directly proportional to the number of Boos in his vicinity.

Luigi's Mansion
Prior to the events of Luigi's Mansion, the ghost hunter Professor E. Gadd had managed to capture Boolossus, one of the biggest and strongest Boos in King Boo's forces. Of course, this had greatly angered the Boo leader, and the ghost orchestrates a rescue attempt. Meanwhile, Professor E. Gadd brings Boolossus to his lab in Boo Woods. Using a special device called a Ghost Portrificationizer, E. Gadd seals Boolossus in a portrait and hangs the new piece of art in his Gallery.

Eventually, King Boo and his forces attack the laboratory. The Boos reverse the settings of the Portificationizer and release Boolossus from his portrait prison. King Boo, in an act of revenge, then orders that all the ghosts that E. Gadd had captured in his travels should be freed as well. After releasing all of the portrait ghosts and reversing years and years of E. Gadd's work, King Boo magically creates a huge mansion out of thin air, and places it right next to the professor's lab. The Boo leader, his Boo minions, and the portrait ghosts recently freed from their prisons, decide to inhabit the mansion. With a new place to haunt and an army of new ghosts courtesy of released portrait ghost Vincent Van Gore, King Boo decides to enact a new scheme. With his newfound resources, King Boo creates a plan of revenge against old rivals of the Boos. King Boo devises a plan to capture both Mario and Luigi, the defenders of the Mushroom Kingdom.

Hoping to recapture Luigi, King Boo sends the plumber a letter. The message states that Luigi had won a mansion in a contest and provides the location of the prize. Of course, Luigi is skeptical of such a reward, as he does not recall entering any contest; however, he is excited nonetheless. He asks his brother Mario to investigate the mansion, and said he would arrive shortly thereafter. As such, Mario, along with a few Toads, ventures to the mansion. Unfortunately, Mario is instantly overwhelmed by King Boo's forces and is captured. King Boo then imprisons the great hero of the Mushroom Kingdom in a portrait, just like the Boo leader's minion Boolossus was previously. The imprisoned Mario is placed in the Secret Altar in the basement of the mansion. Of course, King Boo wishes to add another painting to his collection: the portrait of Luigi.

While waiting for the arrival of Luigi, King Boo and his Boo minions decide to rest behind a secret door in the floor of the Storage Room. When Luigi arrives in the room, and reveals the secret door, the Boos spring out from the floor, enraged after being awakened from their slumber. However, the Boos (including King Boo) break off their surprise attack when they notice the Poltergust 3000 on Luigi's back. The special ghost-capturing weapon was previously given to Luigi by Professor E. Gadd, who wants the plumber to recapture the portrait ghosts. The Poltergust 3000 is one of the few things King Boo fears, and he, along with the other Boos, fly off in different directions and hide in the mansion. The Boo leader himself travels to the Secret Altar in the mansion's basement. While in the protected room, King Boo amuses himself by watching Mario's pathetic pleas for help.

The path to the Secret Altar is locked by a special key in the possession of Vincent Van Gore, who has locked himself in the Artist's Studio on the third floor of the mansion. After capturing the ghost and retrieving the key, Luigi discovers that he needs more than a key to access King Boo's lair. If the green-clad ghost hunter attempts to enter the Secret Altar without catching a certain number of Boos, King Boo himself would materialize before Luigi and blow the plumber away to the Foyer, the entrance of the mansion. However, since King Boo's power was directly related to the number of Boos in the mansion, Luigi could weaken the Boo leader by capturing the Boos hidden in the various rooms. After Luigi captures at least forty of the mansion's fifty Boos, King Boo would lose his ability to blow the ghost hunter away from the Secret Altar. As such, with his Poltergust 3000 in hand, Luigi enters King Boo's lair and prepares for a final showdown.

Upon entering the altar, Luigi notices King Boo staring at his most prized possession: the Mario painting. However, King Boo turns to Luigi and states his desire to complete his set and add a Luigi painting to the collection. After saying this, King Boo flies into the Mario painting hanging on the wall. Strangely, the figure of Mario transforms into the form of Bowser, and the new Bowser painting inhales Luigi into the canvas. After entering the painting, Luigi is transported into a strange arena that resembles the mansion's roof. The green-clad hero is in for an even bigger shock when none other than the colossal form of Bowser appears before him. In reality, this isn't really Bowser, but King Boo is inside the lifelike decoy/facsimile of the hulking beast, secretly controlling the Bowser "disguise" from behind the scenes.

King Boo uses this Bowser disguise to attack the heroic Luigi, shooting flames at the green-clad plumber, and even attempting to inhale Luigi into its mouth. The decoy also possesses the ability to create three large spiked bombs out of thin air, and toss the explosives at Luigi. The hero knew he had to fight back, and used his Poltergust 3000 to pull in one of the spiked explosives and release it into the beast's mouth. The result of this attack blasts off the head of the seemingly mechanical Bowser decoy, knocking King Boo out of Bowser's body. Exposed to the power of the Poltergust 3000, Luigi begins to deplete the ghost's five hundred hit points. Unfortunately, Bowser's head would hover around the arena and shoot ice blasts at Luigi (by measn of King Boo's magic). If frozen, Luigi could shake himself free from the icy prison. He would have to be quick, as he took damage every second he was frozen. Eventually, King Boo would fly back into the dormant Bowser body and the head would reattach itself, resuming the fight and piloting the decoy again. Luigi repeats the same process, slowly weakening the ghost, but after King Boo's life fell below two hundred HP, the head of the machine would reattach backwards whenever he returned to the Bowser body, causing the Bowser decoy to run around aimlessly, destroying everything in its path. Eventually, the Bowser body would put its head on correctly and resume the fight.

After a long and difficult battle, Luigi manages to completely drain King Boo's HP and capture the ghost leader inside the Poltergust 3000. Without the presence of King Boo, the Bowser disguise collapses lifelessly onto the ground.

After the battle, Luigi picks up King Boo's crown, worth 5000G (the value of only one Gold Coin) and adds it to his treasure collection. Upon returning to the mansion, the green-clad ghost hunter also picks up the Mario painting and quickly travels back to Professor E. Gadd's lab. In the lab, Luigi connects the Poltergust to the professor's Portrificationizer, dumping its ghostly contents into the machine. Surprisingly, not only did the spirit of King Boo appear in the Portrificationizer, but what appeared to be the Bowser disguise also materialized. With King Boo captured and imprisoned, Professor E. Gadd hangs his new portrait in the most elegant room of his gallery. In the end, Mario is finally released from his portrait and Luigi emerges from his adventure a true hero.

Luigi's Mansion 2
King Boo has been confirmed to appear in the 3DS game, Luigi's Mansion 2, probably as the main antagonist.

Super Mario 64 DS
King Boo appears in the Super Mario 64 remake, Super Mario 64 DS. As the boss who locked Luigi away, he infests Princess Peach's Castle and wears a large crown and has a distinct cackle - the same laugh that would be heard later when Luigi faces the Boo leader during the events of Luigi's Mansion. However, when the game was translated to English, the King was given the incorrect title, Big Boo. In Mario Kart DS, this exact same enemy returns along with some other Super Mario 64 DS bosses. He is given the proper name of King Boo, as he was in the Japanese version.

Regardless, this Big Boo aids Bowser in his conquest of Peach's Castle by capturing Luigi and imprisoning him in Big Boo's Haunt. Specifically, the green-clad plumber is imprisoned behind a painting of himself inside the haunted mansion. Mario eventually fights King Boo in an effort to free Luigi. To defeat the ghost leader, Mario has to follow King Boo's movements in the arena's mirror and stomp the ghoul when he comes too close. Ultimately, Mario saves his brother from King Boo's clutches and together (along with Yoshi and Wario) they defeat Bowser and save Princess Peach.

This may have been Mario's first encounter with King Boo, as the remake of Super Mario 64 would logically take place at the same time, and take its place in the game chronology. He also attempted to imprison the Mario Bros. in a painting in Luigi's Mansion since he said that he had had past encounters with them.

Super Mario Sunshine
"King Boo" is the leader of the Boos on Isle Delfino and appears as a boss in Sirena Beach, the sixth world of Super Mario Sunshine. He is apparently made from yellow goop, as can be seen during his defeat. This game also notes that he dislikes spicy food[1], which serves as the key to defeat him.

He is named King Boo by the American localization team. However, the original Japanese version assigns a unique name to this character (ボステレサ, meaning Boss Boo), signifying that this King Boo is a separate entity from all other incarnations of King Boo.

Mario Kart: Double Dash!!
King Boo is an unlockable character in the racing game Mario Kart: Double Dash!! This is his first appearance in a spin-off and would result in his frequent appearances in the Mario Kart series (he appears as a playable character in every Mario Kart following this game except for the DS version, where he appeared as a boss in a mission). Despite being a ghost, King Boo is classified as a heavyweight driver, likely due to his large size. His partner is Petey Piranha, and both have the ability to use any other character's special item (if they were going to get a special, it would be randomly chosen, based on their race position). Of course, this means that they possess no unique special item of their own.

King Boo's personal kart is the Boo Pipes, which is basically a gray version of Petey's Piranha Pipes kart, but with an image of a Boo instead of a Piranha Plant where the item-using partner would stand. However, the more important difference between the two is that, while the Piranha Pipes has high speed and low acceleration, the Boo Pipes has it the other way around; it has low speed and high acceleration, which is quite odd for a heavy kart.

Oddly, when partnered with Petey Piranha, King Boo appears quite smaller than Petey. This is most noticeable before the race starts if he is not the driver. Yet, if partnered with another character, he appears much larger than the other character. He also appears to slightly shrink in size when he becomes the driver. On the "true" "Thanks for Playing!" screen (after beating the Special Cup with a Gold Trophy while all other cups already have a Gold Trophy), King Boo appears chasing Wario and Waluigi, and the pair seem very frightened.

Mario Kart DS
In the game Mario Kart DS, King Boo battles against Princess Peach in Mission mode, adopting a much deeper and sinister laugh than the average Boo. As Peach, driving in her kart, attempts to collect fifty coins on the Lava Arena, King Boo would circle around and attack the princess, stealing some of her coins and making all the other, uncollected coins disappear. To steal them back, Peach has to drive into King Boo, making him transparent, and then drive through him again, retrieving her coins again. However, he would soon appear again a few moments later. After collecting fifty coins, King Boo would admit defeat and Peach would win the battle.

Mario Kart Wii
King Boo returns in Mario Kart Wii as a large-sized driver, and is unlocked by completing the Star Cup in 50cc. He features a good handling bonus and a small off-road bonus, which comes in handy for vehicles like the Offroader, Wario Bike, and Phantom. He is used as the Staff Ghost on the SNES Ghost Valley 2 course. In the credits, he appears driving the Aero Glider on the SNES Ghost Valley 2 course.

King Boo is one of very few characters to have his "standing sprite" (on the Character Select screen) altered from Mario Kart: Double Dash!! In this case, his tongue is not sticking out of his mouth the whole time like before; now, before selecting him, his tongue would be in his mouth. Other characters whose sprites were altered include Birdo (whose bow was made larger), Wario (who now has short sleeves), and Waluigi (what he does when being selected in Mario Kart Wii seems much different from Mario Kart: Double Dash!!, though it is slightly the same).

Mario Superstar Baseball
King Boo is a playable character in Mario Superstar Baseball and a member of Wario's baseball team. He does not need to be unlocked. He is a power hitter; he can use his white, Boo-like baseball bat (topped with a crown) to hit long outfield drives and even homeruns. King Boo has chemistry with Boo and Petey Piranha, and he has bad chemistry with Luigi. However, like Boo, his hits are usually very curved and cause them to be fouls most of the time.

Mario Super Sluggers
King Boo reappears in Mario Super Sluggers and is once again a member of Wario's baseball team. In Challenge Mode, he appears immediately after the player defeats Bowser Jr. at the Wario City stadium, however, he is uninterested in joining the player's team unless they have some Boos with them. This is accomplished by finding both Boo and the Mini Boos (an item), and upon seeing them, King Boo joins. In this game, King Boo has chemistry with Petey Piranha, Boo, King K. Rool, and Wiggler, but he has bad chemistry with Mario, Luigi, Baby Mario, and Baby Luigi. It is unknown why he has chemistry with King K. Rool, but it is possible that the two see each other has ally kings rather than rival kings.

An interesting thing to note is that his baseball bat does not have a physical crown on it anymore, and now it is represented as a crown picture above the "Boo mouth" picture from before.

Super Princess Peach
King Boo aids Bowser in another one of his schemes in Super Princess Peach. During the events of the game, Bowser's forces overwhelm and capture both Mario and Luigi, along with a cavalcade of Toads. Although King Boo does not get to directly watch over Mario or Luigi, he is given a captured Toad to guard (Mario is Bowser's prisoner, while Kamek protects a captured Luigi). Without the Mushroom Kingdom's greatest heroes, it is up to Princess Peach, the leader of the Mushroom Kingdom, to take matters into her own hands.

After adventuring through Vibe Island, Peach discovers the location of King Boo and engages the ghost leader in combat. During the battle, the Boo leader fires blue homing fireballs at the Princess. Toadstool could damage the King Boo with direct light, which is made by having his own flames light candles. After a few attacks, King Boo will unleash his vibe: Gloom. He'll cry, which would extinguish the candle flames. After enough attacks, King Boo succumbs to Peach's assault. With the threat of King Boo eliminated, Peach rescues the captured Toad and continues her campaign against Bowser's forces. Ultimately, Peach defeats both Kamek and Bowser, and rescues the heroes Mario and Luigi.

In this game, King Boo is described (and appears) as a huge Boo, suggesting he may not be the same as the original King Boo from Luigi's Mansion.

Mario Party 8
King Boo makes his first appearance in a Mario Party game in Mario Party 8. He is the star-giver of his own course King Boo's Haunted Hideaway. He hides in one out of three altars and he gives the player a Star for ten coins if they can find him where he is hiding. Afterwards, he will "summon the bizarre" and disappear, causing the player to jump into a Warp Pipe back to the starting point. This "makeover mojo" causes the whole layout of the course to change. Additionally, when the players loses the mini-game Pickpocket Pinball, the mouse sounds like King Boo. The player can purchase King Boo sounds from the Fun Bazaar along with a figurine titled "King Boo's Revenge".

Mario & Sonic at the Olympic Winter Games
King Boo appears as the first and sixth (in Individual Festival mode) rival in Mario & Sonic at the Olympic Winter Games. King Boo races the player in Alpine Skiing Downhill in both Individual and Group Festival modes but he only races the player in Giant Slalom in the Individual Festival mode. King Boo can fly and has no skis so he goes down the hill quite smoothly. If the player loses to him, the guide (either Cream or Toad) will say that it is unfair because King Boo has no skis. In Adventure Tours in the DS version, King Boo is the miniboss in Polastraits. When he is approached, he challenges Luigi to an Alpine Skiing Downhill race because he messed with his minions earlier. In this version, King Boo is transparent so the player can ski through him. This may make the challenge easier since there is no other skier to bump into. He also appears slightly larger than in his other appearances.

Physical Appearance
King Boo's appearance has changed throughout his video game history. In his debut in Luigi's Mansion, King Boo has red eyes shrouded in darkness, a blue tongue, two vampire-like fangs, a purplish complexion, and a ruby crown. In recent appearances, the ghost leader resembles a white, normal-looking Big Boo with a golden crown (though much larger), as he did in the "Big Boo Battle" in Super Mario 64 DS, which remains as his current appearance to this day (though artwork for Luigi's Mansion 2 shows him with his Ruby Crown). The change of crown was most likely due to the fact that after he was defeated in Luigi's Mansion, Luigi took his original crown as a treasure.

Personality
King Boo is shown to not hold a grudge, even when Luigi defeated him in Luigi's Mansion. He is one of Bowser's most trusted minions because of his intelligence and power. He also says that he fears nothing except the Poltergust 3000, although in Super Mario 64 DS he admits that Wario scares him, rendering the previous statement false. Also, in Mario Super Sluggers, King Boo says that he finds little Boos cute. In Mario & Sonic at the Olympic Winter Games, he says that he is undefeatable at the Alpine Skiing events, though this is proven false when the player beats him.

Traits and Abilities
Besides possessing the abilities of other Boos, including the ability to teleport, King Boo has a number of other magical powers. Notably, King Boo's power increases when he is in the presence of other Boos. For example, King Boo had the power to blow Luigi to the Foyer only when enough Boos were in the mansion. King Boo also has the incredible power to materialize things out of thin air, including highly detailed mansions and lifelike robotic replicas of some of Mario's enemies (and using them himself by means of magitech). He has also shown the ability to create Boos, bubbles, and blue fire, which he spits out of his mouth. King Boo also appears to be a good Alpine Skier, as he states that he is exceptional at that event, though this remains questionable due to his lack of skis.

Although King Boo is a lot larger than regular Boos, he is not the largest of the Boos. However, even gigantic Boos like Boolossus follow his leadership, despite their superior size. This is likely because he is the most intelligent and the most powerful of the Boos. King Boo seems to have a passion for gambling, as the entrance to each wing in Luigi's Mansion was modeled after a playing card suit (spade, club, heart, and diamond), and in Super Mario Sunshine, "King Boo" (this is possibly not him) appears in Hotel Delfino's Casino Delfino.

King Boo, possibly due to his large size, appears with a rather high power stat in many of his spin-off appearances. This is most noticeable in the Mario Baseball series, where he is able to hit home runs with relative ease.

King Boo has an extreme dislike for the Mario Bros., due to their constant intervention in the plans of the Boo leader and others of his kind. Lastly, King Boo has a distinct cackle, which is significantly lower in pitch than other Boos.

King Boo is also shown to be able to regenerate from his crown in Super Princess Peach.

Boo Leadership
Although he commands a large band of Boos, not all Boos call King Boo their leader. Some Boos work directly for Bowser. These Boos are most likely the Boo enemies that have appeared in earlier games before King Boo's debut. A small band of Boos are allied with Lady Bow; these ghosts live peacefully with the other denizens of the Mushroom Kingdom (although they still like to scare other species, especially Toads, from time to time).

Mario
King Boo and Mario have known each other for a long time. If Super Mario 64 DS took place at the same time as Super Mario 64, then the two have known each other for years. Also, King Boo imprisons Mario in a painting as a consequence for messing with his plans in the past.

Luigi
When Mario goes to Luigi's new mansion to investigate, he is captured by King Boo. Therefore, Luigi has to go rescue Mario by defeating the Boo leader. King Boo longs for Luigi in the painting too, for Luigi also has past dealings with King Boo. Ever since Luigi's Mansion, the two have shared bad chemistry.

Petey Piranha
Petey Piranha and King Boo have shared chemistry in many spin-off games; the two are default partners in Mario Kart: Double Dash!! and they share chemistry in both Mario Superstar Baseball and Mario Super Sluggers. Though the two appear to be friends, their relationship with each other still remains quite a mystery.

Bowser
King Boo is known to be one of Bowser's right-hand men due to his intelligence and power over Boos. This was shown in Super Mario 64 DS where he was guarding Luigi's key. Also, King Boo was one of the bosses in Super Princess Peach, a game where Bowser had kidnapped the Mario Bros., so he must've called upon King Boo to hinder Peach's quest. Also, in Luigi's Mansion, King Boo participates in the final battle in a Bowser decoy (most likely a False Bowser), which he controls. It breathes fire and spits out large mines. Since King Boo was allowed to use a machine replica that looks like Bowser, he must have given the Boo his permission to use it; on the contrary, King Boo might have constructed it without Bowser's knowledge.

Wario
Though no direct interactions have been shown, King Boo and Wario seem to have something to do with each other. In the ending picture to Mario Kart: Double Dash!!, King Boo is shown chasing Wario and Waluigi, scaring the two. Also, in both Mario Baseball instalments, King Boo is on Wario's team, though this may not be very reliable since Wario's team may be considered the "misfit team"; there is no noticeable theme through his team (Mario's is Delfino-based, Peach's is Toad-based, DK has characters from the DK Series, and Bowser has his minions).

Professor E. Gadd
King Boo originally stated that the only thing that scared him was the Poltergust 3000, which Prof. E. Gadd had invented. Also, before the events of Luigi's Mansion, Prof. E. Gadd had captured one of King Boo's greatest minions, Boolossus. So, King Boo plotted an attack on Prof. E. Gadd's laboratory, and set free all of Gadd's years of ghost-capturing work. This shows that King Boo and Prof. E. Gadd are not on good terms with each other.

Quotes

 * "White gloves! A cute little moustache! Soft shoes! How did you get out of my...? ... Huh? Wait just a second... Your clothes are... green... Hey, you must be Luigi! Whoa, you had me a bit confused for a moment there!" - Luigi's Mansion
 * "What? You want me to release Mario? Riiiiight." - Luigi's Mansion
 * "It's true what they say about fine art... it takes utterly refined sensibilities to truly appreciate it!" - Luigi's Mansion
 * "The way you plead for help, Mario... I find it so... satisfying." - Luigi's Mansion
 * "...Seriously, though, who would actually believe that mansions get given away in contests?! Talk about stupid! What do they feed you Mario brothers anyway... gullible soup?" - Luigi's Mansion
 * "I swear it... I shall fear no mere house-cleaning device!!" - Luigi's Mansion
 * "There are no exits. You may as well wander in here forever..." - Super Mario 64 DS
 * "I love scaring wimpy humans." - Super Mario 64 DS
 * "Eek! What's this!? Your face... It would even scare a ghost. How horrible! You've got it backwards... I do the scaring around here!" - Super Mario 64 DS
 * "Aw... Little Boos are so cute!" - Mario Super Sluggers
 * "Bring me my 10 coins fools!" - Mario Party 8
 * "If you hear me laughing, that means you're doomed!" - Super Mario 64 DS

Mario Kart: Double Dash!!
Website Bio: ''If you're not afraid of ghosts, you will be once King Boo is through with you. To unlock him, finish the Mirror Mode Star Cup with a 1st place win.''

Mario Super Sluggers

 * Team Captain: No
 * Player Type: Power
 *  Special Skill: Teleport
 * Good Chemistry: Boo, King K. Rool, Petey Piranha, White Mii, Wiggler
 * Bad Chemistry: Baby Luigi, Baby Mario, Luigi
 * Stats
 * Batting: 7/10
 * Pitching: 7/10
 * Fielding: 3/10
 * Running: 4/10
 * Default Bat: Right
 * Default Glove: Left
 * In-Game Bio: A decent player with poor defense.
 * Collectible Card Info: Haunting Luigi since he first set foot in the mansion, King Boo doesn't have the stamina for late innings, but he's a talented player nonetheless. As it is with many ghosts, he is not well-liked by other players.

Gallery
For this subject's gallery, see here.

Trivia

 * When King Boo says, "I don't plan to give up my favorite decoration. I like Mario where he is." is a quote derived from Star Wars VI Return of the Jedi, when Jabba said, "I don't plan to give up my favorite decoration. I like Captain Solo where he is."
 * The two games that King Boo was playable in the Mario Kart series were the same games where Boo wasn't an item.
 * The King Boo character in Super Mario Sunshine was named "Boss Teresa" (Boss Boo) in the Japanese version. Judging from his different name and distinct appearance, it is likely to be another character entirely, though the game makes several references to Luigi's Mansion.
 * For some reason, King Boo's voice is sometimes sped up in games like Mario Kart: Double Dash!!, Mario Kart Wii, and Mario Super Sluggers, while in such games like Super Mario 64 DS, and Mario Kart DS, it is unaltered. This is quite similar to Bowser's voice being slowed down in some games, while in others it is not.
 * Despite the fact that his original ruby crown looked very valuable, it was really only worth one Gold Coin.
 * If King Boo is captured in a Silver or Bronze Frame, the portrait will show him wearing his crown, even though Luigi took it when he trapped King Boo in the Poltergust 3000.
 * The rather mechanical Bowser decoy that King Boo utilizes against Luigi may be loosely based on the False Bowsers from Super Mario Bros., or may very well be just that, as the enemies in that game probably used theirs similarly (without the sorcery of King Boo).