Professor E. Gadd

"I'm getting too old for this ghost-catching tomfoolery."

- Professor Elvin Gadd

Professor E. Gadd, full name Professor Elvin Gadd (sometimes Dr. E. Gadd), is the scientist first appearing in Luigi's Mansion and founder of Gadd Science, Inc. He always speaks in ambiguous gibberish (supplied by Kazumi Totaka, who took inspiration from Animal Crossing 's "Animalese" when inventing the voice ), but the translation is always provided in a text box.

Background
Professor Elvin Gadd used to live on the foothills of the Thwomp Volcano, as depicted in the game Mario & Luigi: Partners in Time.

The Mario Bros. come back in time and end up saving E. Gadd's lab from burning down when fire blocks erupted from the Thwomp Volcano. He then helps the Mario Bros. by inventing the Hydrogush 4000. Although he doesn't directly invent the Hydrogush 4000, his older self does in a complex way: Young E. Gadd starts to get an idea after a totally unrelated event happened during the present time, which transfers to his future self, causing Professor Elvin Gadd to send water from the Hydrogush 4000 via Time Hole and calm the erupting Thwomp Volcano. After all this excitement, the twenty-year-old E. Gadd moves to Boo Woods.

Luigi's Mansion
Many decades later, in Luigi's Mansion, Luigi enters the mansion and is saved from ghosts by a strange old man wielding a vacuum cleaner. Professor E. Gadd reveals he lives in a house near the mansion, where he researches his favorite subject: ghosts. Luigi explains his brother Mario is missing within the house, and the professor decides to help Luigi by giving him two of his inventions, the Poltergust 3000 and the Game Boy Horror. The professor continues to help Luigi throughout the game, giving him help and tips.

Super Mario Sunshine
In Super Mario Sunshine, when Mario finds F.L.U.D.D, it says: "Thank you for purchasing this item from Gadd Science, Inc." Later, Bowser Jr. says he got his magic paintbrush from "a strange old man in a white coat." This is a fitting description of Professor E. Gadd, which is further confirmed when F.L.U.D.D seems to react in surprise to the statement. It is unknown if E. Gadd actually gave Bowser Jr. the Gaddbrush, or if Bowser Jr. stole it from him, but the latter theory is more likely. There is a symbol both on the Magic Paintbrush and F.L.U.D.D, showing a face and hairstyle similar to E. Gadd's, which seems to be the Gadd Science, Inc., logo. It appears on many of E. Gadd's other inventions, as well as the boxes for F.L.U.D.D.'s nozzle upgrades.

Mario & Luigi: Superstar Saga
In Mario & Luigi: Superstar Saga, the professor makes an appearance supplying the brothers with an array of accessories to help them along their way each time they drink at Starbeans Cafe, a coffeehouse that he owns. However, it has been found that originally, the game was only going to feature Professor E. Gadd once, the first time Mario and Luigi get a drink; in all of the future times, it would different characters would have appeared. These characters are Wario, Samus Aran, Fox McCloud, Link, an Excitebike racer, and Captain Olimar.

Mario & Luigi: Partners in Time
In Mario & Luigi: Partners in Time, the professor debuts his newest invention to the Mushroom Kingdom, a Time Machine. However, when Princess Peach ends up stuck in the past, E. Gadd provides the brothers a suitcase enhanced with artificial intelligence named Stuffwell to help them on their quest. The heroes later meet young Elvin Gadd, who is researching the behavior of the Thwomps at Thwomp Volcano. After his lab is destroyed by the eruption of the volcano, he mentions his interests in studying ghosts, and that he would be buying a lab at the edge of Boo Woods, nodding toward his first appearance in Luigi's Mansion.

Mario Party series
A flashlight known as the Gaddlight was used to scare away Boos when they tries to steal a Star or coins in Mario Party 4. A magic wand bearing Gadd's logo later appears in Mario Party 7, and players can use the coins earned in the mini-games to buy Professor E. Gadd's many "Gaddgets" in Mario Party Advance.

Professor E. Gadd's garage was a mini-game in Mario Party 5 and was then featured as a game board in Mario Party 6. In Mario Party 6, when a player lands on a ? space E. Gadd will appear and let them try one of his inventions.

Mario Kart series
E. Gadd's inventions are sometimes used as items in the Mario Kart series.

Mario Kart Arcade GP
E. Gadd makes a small cameo in Mario Kart Arcade GP in the background of the Diamond City course in the Wario Cup. His face, the logo of Gadd Science, appears on a building.

Inventions
A vacuum from Mario Party 7. It is a capsule item exclusive to Wario and Waluigi. It doesn't look much like the Poltergust 3000. Rather, it is yellow and purple (much like the two characters that use it), and features the E. Gadd logo. It is used to steal coins from other players.
 * Coin Vacuum

A handheld device that bears a striking resemblance to a Nintendo DS used briefly by E. Gadd to find Princess Peach in Mario & Luigi: Partners in Time. It has the ability to pinpoint which time period someone is trapped in. One of the Toads thinks he just made it up. Also, when Professor E. Gadd turns on his Hydrogush 4000, he uses a DS-like device.
 * DS Time Radar

Special parts that can be bought in the Super Duel Mode of Mario Party 5. They include the E. Gadd body, E. Gadd Jet, E. Gadd Engine and E. Gadd gun.
 * E. Gadd Battle Machine

E. Gadd's garage is the garage he had in Mario Party 6. He also keeps his numerous inventions there. It also appears as a Rare Mini-Game.
 * E. Gadd's Garage

The Flash Liquidizer Ultra Dousing Device, or F.L.U.D.D, is a water-spraying backpack used by Mario in Super Mario Sunshine. It has various nozzle attachments which can be collected by breaking open boxes with E. Gadd's logo on the front. F.L.U.D.D also has notable artificial intelligence and the ability to communicate with a voice. In certain ways, F.L.U.D.D functions much as Navi did in The Legend of Zelda: Ocarina of Time.
 * F.L.U.D.D

The Gaddgets appeared in Mario Party Advance. There were 80 total, and were very similar to the toys in the WarioWare games.
 * Gaddgets

A flashlight that is used to scare away Boos when they try to steal a Star or coins in Mario Party 4.
 * Gaddlight

The Game Boy Horror is a portable device from Luigi's Mansion that bears a striking resemblance to the Game Boy Color containing a built-in camera which E. Gadd can use to watch the action from the safety of his lab and contact Luigi. It also stores data including a map and anything Luigi has collected, and contains a special radar called the Boo Radar to find hidden spherical objects.
 * Game Boy Horror

The Game Boy Horror SP is a upgraded version of the Game Boy Horror, given to Mario by E. Gadd in Mario & Luigi: Superstar Saga. It is another portable device (this time bearing striking resemblance to a Game Boy Advance SP). It increases the likelihood of earning rare items in battle. It was originally going to be simply the Game Boy Horror.
 * Game Boy Horror SP

A pale blue jacket that, when worn, turns characters into a ghost. When E. Gadd wore this in Mario & Luigi: Superstar Saga, Luigi got scared and used the Poltergust 3000 to vacuum him up.
 * Ghost Gown

The Ghost Portrificationizer is a large machine which works in conjunction with the Poltergust 3000. Certain ghosts captured can be entrapped in portraits to be hung in E. Gadd's gallery. The machine also works in reverse, which was utilized to free Mario from the painting he had been trapped in by King Boo. E. Gadd also commented that it took him twenty years to build.
 * Ghost Portrificationizer

A large water pump used in Mario & Luigi: Partners in Time. It's not portable like the FLUDD, but it does have a lot of power.
 * Hydrogush 4000

The Magic Paintbrush is used by Bowser Jr. (as Shadow Mario) in Super Mario Sunshine. It is a large paint brush with the ability to paint various colors and even create enemies. It is unclear why the brush was made as well as why it was given to Bowser Jr., though some fans claim he stole it or E. Gadd was tricked by Bowser Jr. using his Mario costume. In Mario Power Tennis, Mario Hoops 3 on 3, and Mario Super Sluggers, Bowser Jr. uses his Magic Paintbrush to perform special moves.
 * Magic Paintbrush

The Poltergust 3000 is a modified vacuum cleaner designed to entrap ghosts. It also has a "blow" function which allows it to expel elements it sucks up such as fire, water, and ice. Luigi uses this in Luigi's Mansion to defend himself from the many ghosts; it also makes a return in Mario Power Tennis where Luigi uses it as his defensive Power Shot, using its suction power to retrieve the ball.
 * Poltergust 3000

The Super Poltergust 3001 is an advanced version of a Poltergust 3000. It has the same functions as the Poltergust 3000, but is much larger thereby allowing it to be ridden on. When ridden, it hovers over the ground. It is capable of moving at high speeds. E. Gadd briefly uses it in Mario & Luigi: Superstar Saga.
 * Super Poltergust 3001

The Poltergust 4000 of the vehicles used by Luigi in Mario Kart DS to race in. It is similar to the Super Poltergust 3001, though it does not float. The "barrel" of the car is the area Luigi sits on, and the nozzle rests on the ground. Emblems are placed on both sides of the barrel.
 * Poltergust 4000

The café in the Beanbean Kingdom, founded and owned by E. Gadd. Strangely enough, it does not have any toilets. At one point, E. Gadd puts up a larger-than-life-size portrait of himself. Every time Mario and Luigi mix a new drink, E. Gadd visits.
 * Starbeans Café

An intelligent suitcase used by the Mario Bros. on their quest in Mario & Luigi: Partners in Time. Its purpose is to manage the brothers' inventory and display their current status. It also helps the brothers by activating the Shroob Saucers that you use in the game, and eventually near the end develops the ability to return to the past before you rescue Princess Peach. It is known to use large and overly complex made-up words when he speaks, and upon ending its speeches, says "BACK TO ADVENTURE!"
 * Stuffwell

A magic wand in Mario Party 7, which has the E. Gadd logo on it. It is exclusive to Boo and Dry Bones. It was used to turn the characters invisible, making them impervious to traps, and to double their rolls on Dice Blocks for two turns.
 * Surprise Wand

Used by Princess Peach to visit the past at the beginning of Mario & Luigi: Partners in Time. It is powered by the Cobalt Star. It breaks at the beginning of the game but is repaired after the Shroobs are defeated.
 * Time Machine

Trivia

 * In The Super Mario Bros. Super Show! episode "Robo Koopa", there is scientist named Dr. Nerdnick who bears a passing resemblance to E. Gadd due to his similar appearance and the fact that he too speaks in incomprehensible gibberish.
 * Almost all of Professor Elvin Gadd's inventions are yellow, such as F.L.U.D.D, the Hydrogush 4000, the Gaddlight and parts of the Coin Vacuum.
 * In Super Smash Bros. Brawl, one of the names that can appear whenever a player presses the random button when they're naming their custom stage is "EGADD."
 * Glasses with swirls are often seen in Japanese media., and are a feature Professor Elvin Gadd shares with Professor Frankly, Fawful, and Iggy Koopa
 * His name comes from the minced oath "Egad!"
 * Occasionally, Professor E. Gadd's voice overs will include "Oyamaa," which is both his Japanese name and an exclamation of surprise. This happens even in overseas releases.