Many thousands of years ago, Antasma was once a normal bat on Pi'illo Island. At some point, however, he managed to feed off of a Pi'illo's nightmare, turning him into the Bat King. The Pi'illo, which were not taking their duty to guard the Dream Stone and the Dark Stone seriously enough, were thus caught off guard when Antasma suddenly stole the latter in order to fulfill his twisted dreams. The Pi'illos, along with the Zeekeeper, ultimately engaged the bat king in battle and managed to imprison him into the Dream World; however, just before his seal was complete, Antasma shattered the Dark Stone, causing the chunks to rain down all over the island. The shards of the Dark Stone turned all the Pi'illo they touched into stone , causing the demise of the Pi'illo civilization and triggering most subsequent events in the game.
Mario & Luigi: Dream Team
Antasma (referred to as ???? in-game) first appears on the blimp ride to Pi'illo Island during a nightmare dreamt by Luigi. He initially appears as his pillow form and after swatting almost everyone off the blimp transforms into his humanoid form and attacks Mario, thus replacing Bowser from previous games as the tutorial boss. After a brief battle, Antasma is defeated, but pierces through the bottom of the blimp as he floats away, causing it to plummet towards the island, at which point Luigi's dream ends.
Antasma is not seen again until Prince Dreambert's pillow is found and Luigi sleeps on it, opening a a portal to the Dream World. From there, Antasma calls out to Princess Peach, and proceeds to immobilize and suck her in when she approaches the portal. Mario gives chase into Dreamy Pi'illo Castle, but Antasma distracts him with a dream counterpart of him he creates on the spot, and opens up a hole to Dream's Deep after Mario defeats his counterpart, which he promptly departs to and seals up behind him. Despite this, Mario manages to save Prince Dreambert whose Nightmare Chunk is found later on in the Dream World, who explains to Mario what had transpired the last time Antasma had tried to conquer the world and worries Antasma was Peach's kidnapper.
With the help of Eldream and his pet, Mario manages to reach Dream's Deep, and doesn't take long for Mario, Dreamy Luigi, and Prince Dreambert to reach Antasma; before he can react, however, Bowser appears and gives him a solid punch that knocks him away briefly. Antasma retaliates by leeching Bowser's face and screeching loudly, flooring everyone except Bowser, Dreambert, and himself, and then speaks for the first time in the game. He reveals that he had kidnapped Peach to exploit her power and escape the Dream World so he could conquer the Real World, but that the appearance of Bowser - who, unlike Peach, is both strong and evil - caused him to change his plans, and he suggests that they work together. Bowser initially disagrees to this and insults Antasma, but Antasma ultimately convinces Bowser to form an alliance on the basis of giving him greater powers. Antasma then possesses Bowser, and together they manage to defeat Mario and Luigi before leaving the Dream World.
Later, after Eldream and Dreambunny escort the Bros. and the princess out of the Dream World, Prince Dreambert and Starlow recap that Antasma has escaped the Dream World, formed an alliance with Bowser, and explains the same story he told earlier to Peach, with Eldream adding that Bowser and Antasma were most likely going to go after the Dream Stone next. Mario and Luigi hurry off to Dozing Sands to stop them from acquiring it, but unfortunately arrive too late - Antasma and Bowser were already at the Dream Stone pedestal, and gloat over having already grabbed the gem.
To figure out where the evil duo were planning to go next, Mario and Luigi use the Dreampoint they were standing on to hopefully gather some information about the Dream Stone's new whereabouts. After the Dream Stone Soul informs Luigi that it had been taken to Mount Pajamaja, the brothers sign up for a tour to the mountain's summit and in the end find Antasma - now accompanied not only by Bowser, but also by Kamek and the Elite Trio - at its peak. To channel the Dream Stone's power, Private Goomp turns on a set of speakers that begin to play the Dreambeats, which promptly puts everyone on the island to sleep except for Antasma, Starlow, Prince Dreambert (all three seemingly immune to the noise), Bowser (due to covering his ears) and Mario (who has to actively resist the lullaby). Luigi, who did not manage to resist the noise, falls asleep and with Mario's assistance rolls to a nearby Dreampoint, which Mario enters in order to escape the noise.
After the Dreambeats subside, the Bros. exit the Dream World to immediately encounter Antasma and Bowser by the Dreampoint, who gloat over their now usable Dream Stone. Upon the realization Peach was in danger, the Bros. hurry to Pi'illo Castle in order to protect Peach, who would surely be Bowser's first target. Back at Mount Pajamaja's summit, Antasma and his new allies begin discussing what to wish on the Dream stone to conquer the world with. Antasma suggests that they wish for an impenetrable castle; when this is quickly approved of by everyone else, Antasma wishes for this, which leads to the instantaneous creation of Neo Bowser Castle. Antasma then takes the castle for a 'test-drive', blowing up several islands near Pi'illo island with a large laser cannon situated on the bottom of the castle, sending the inhabitants of Pi'illo Island into a panic.
Although he is mentioned repeatedly after the creation of Neo Bowser Castle, Antasma only reappears again once the Bros. invade the castle. He first appears shortly after Kamek scrambles the castle's doors, ripping open a portal to the Dream World to allow Kamek to escape from Mario and Luigi. After Antasma hides Kamek away for the third time and he is defeated, Antasma manages to convince Bowser to fall asleep on him to use his powerful dreams to power the castle. When the Bros. finally reach the duo, Bowser's dreams are providing such great power that Bowser himself is invulnerable to Real World attacks, and the bros. are forced to enter Bowser's dream to wake him up and weaken Antasma.
After Giant Bowser is defeated, Bowser is awoken and flees with Antasma to the next floor, where upon the Bros. arrival, Bowser reveals that he had been using Antasma all along. Declaring the castle and the Dream Stone to be solely his, Bowser warps to the top floor using the Dream Stone he claimed, leaving a frustrated Antasma to swear revenge for his former partner's betrayal and then challenge Dreambert to a duel. After a duel in the Real World proves indecisive, Antasma rips open another portal to the Dream World and flees inside while warning Dreambert that he has grown stronger: Dreambert follows and is soundly defeated. In Dreambert's stead, Mario enters Antasma's Dream World and confronts him; with the assistance of Dreamy Luigi and Dreambert, Mario eventually vanquishes Antasma. When Mario leaves Antasma's Dream World, Antasma follows a few seconds later, inflates like a balloon, and explodes, ending his schemes for good.
Antasma appears, for the most part, as a bat with a giant grin. At the beginning of the game, though, he appears as a purple cloud, and then a bat. Later in the game, he is shown in his true form, which consist of his cape, bow tie and two claws. In battle, Antasma takes his bat form or a more ghostly looking version of his true form. This form is taller and skinnier and reveals his arms.
In Pillow form, Antasma appears as a purple Pillow with his cape spikes and eyes.
Antasma's speech is based off old Dracula movies with most words having "v"s in them and screaming tics which come from his bat side. He makes careful decisions, since after his imprisonment, such as choosing whose power he needs to help realize his dreams, but can be jumped-on easily when in a false sense of security, such as Bowser attacking him in Dream's Deep and Bowser's betrayal. He has a temper and a strong hate for the P'illo's, especially Prince Dreambert. Others show fear towards him besides the Zeekeeper, who sees him as just a pest.
Antasma has many abilities inside and outside of battle.
In his bat form, Antasma is able to screech ultrasonic waves that will stun a foe or power up an ally. He is also able to carry great weights such as Bowser and fly long distances. This ability is very similar to Cackletta's bat transform ability.
Antasma confronts Mario in this form while attacking Mario with Bowser in Dream's Deep. After performing one of his fire-spewing attacks, Bowser will cough up a cloud of Antasma clones that will surround Bowser. Should Mario or Dreamy Luigi accidentally hit one of the bats, all of the surviving bats will fly to the right side of the screen and then start flying towards the left side, usually attempting to ram Mario; Mario must counter these bats with a hammer. The remaining bats will return to Bowser, possibly healing him for a small amount of damage.
In his true form, Antasma is able to hover and teleport from locations. He is also able to grow vines which he spreads through Neo Bowser Castle to supply power to it from Bowser's dreams. By the end of the game, a wish to the Dreamstone gave Antasma the ability to open portals to the Dream World at will, allowing him to access his stronger battle form.
Antasma appears in his battle form for the final time after Mario enters his Dream Portal, directly transforming from his true form into his battle form. This form of Antasma is far more powerful than his prior forms.
During this third battle against Antasma, Prince Dreambert will heal Mario by 30HP at the start of Mario's attack turn(s). Antasma's turns usually start with him creating a ring of Antasmunchies around him. At the beginning of most turns, after creating the Antasmunchies, Antasma will then proceed to eat at least two Antasmuchies before attacking: each Antasmunchie gives him an increase in attack power. Antasma can also trap Dreamy Luigi in an Antasmunchie and mix them around to prevent the defeat of the Antasmunchie holding him captive. If Antasma eats the Antasmunchie containing Dreamy Luigi, his power increases tremendously, and Mario suffers from reduced stats and cannot perform Luiginary attacks as long as Antasma or his Antasmunchies have Luigi. Antasma spits Dreamy Luigi out after several turns if he manages to swallow him.
The Antasmunchies also assist Antasma in two of his other attacks. If Antasma takes a sufficient amount of damage, he may hang off the top of the screen, raising a shield around him and hibernating to recover health (200 HP per Antasma's attack turn after the turn the move is activated). While Antasma is hibernating, his Antasmunchies will transform into insect-like monsters and will try to ram Mario each turn, lowering his defense if they succeed; this attack must be countered with a hammer. After all the Antasmunchies are defeated, Antasma wakes up and resumes the battle.
Antasma's last Antasmunchie-related attack is to turn them into a ring of explosives. Antasma will create a ring of Antasmunchies, and then proceed to chase Mario. Every so often Antasma will throw the bombs straight in front of him, often re-directing them with his hand: Mario must get in the middle of the ring of Antasmuchies and jump when Antasma makes them explode. Antasma and Mario will both take damage from the shockwave the Antasmunchies create, but if Mario directly touches an Antasmunchie, they will explode, send Mario flying after dealing damage, and end the attack. Notably, the recoil damage Antasma can take from this attack is related to Antasma's attack power, not Mario's: thus, Antasma will take more damage on hard mode than he would in normal mode due to his higher attack power.
Antasma can also turn into a group of bats, whom will all fly towards Mario like in the first battle against him; however, Mario may get a dark cloud around him if he gets hit by the bats, and will fall asleep when the attack ends if this occurs. When this happens, Mario will find himself in a nightmare being chased by a slightly larger Antasma that shoots purple fireballs every so often which must be jumped over. Portals are found throughout the nightmare, and to escape the nightmare Mario has to find the Rainbow Portal, which contains coins and a Super Mushroom; if Mario falls in a purple portal, it takes him into an area with floating sawblades that must be avoided by tilting the 3DS, after which the chase will resume.
Antasma's last attack involves him creating clones of himself, with the real Antasma displaying a large electrical orb in his hand. The Antasmas will then quickly be shuffled into a line and pull their hand out: the real Antasma will fire the orb as soon as he pulls his hand out. The orb can lower Mario's defense, but can be deflected back at Antasma with a hammer.
An upgraded version of Antasma, named Antasma X appears in the Battle Ring, as one of the bosses of Class 2 with Bowser, and Class 8 alone. His color palette has been changed, instead of purple on his body and cloak, it is blue and the eyes are light blue. Antasma X's powers are the same as Antasma's true form, but his stats have increased, as they would with all X bosses.
Names in other languages