Professor Elvin Gadd (usually referred to Professor E. Gadd), is a supporting character throughout the Mario series. He is an incredible inventor and the head of Gadd Science Inc. He speaks in an unrecognizable jumble of words and sounds when he talks to other characters.
Super Mario Sunshine
The professor has another fairly minor role in the story of Super Mario Sunshine, where E. Gadd invents the F.L.U.D.D. for Mario's use in cleaning up Isle Delfino, which was caused when Shadow Mario (actually Bowser Jr. in disguise) obtained the professor's magic paintbrush.
Mario & Luigi: Superstar Saga
In Mario & Luigi: Superstar Saga, he is the owner of the Starbeans Cafe in Beanbean Kingdom. If Mario collects enough beans for the coffee maker, he would test the coffee and give his inventions to Mario, one at a time.
Mario & Luigi: Partners in Time
In Mario & Luigi: Partners in Time, he is the inventor of the time machine that led to the capture of Princess Peach. The younger E. Gadd can be found in the past, after helping him he said something about going to a haunted mansion in Boo Woods. Both the past and present versions of the professor thought of the Hydrogush 4000 during the course of this game (the past E. Gadd used it to extinguish the flames on his laboratory, while the older incarnation used it to pump baby tears into the various time holes to get rid of all shroobified objects).
Mario Party 6
In his only appearance in a Mario Party game, Professor E. Gadd has his own stage called E. Gadd's Garage in Mario Party 6. Professor E. Gadd operates many machines including a giant fan that sucks coins from other players, a machine that launches orbs on random spaces on the board, and, most commonly, his teleporter machine. E. Gadd also runs the Lab Brats mini-game where the player must find other characters within the time limit. E. Gadd will rank the player on how fast the completed the maze.
Luigi's Mansion: Dark Moon
E. Gadd returns as a main character in Luigi's Mansion: Dark Moon. After figuring out that the Dark Moon has been destroyed and the ghosts soon turn hostile, he enlists the help of Luigi to once again help him in his ghost-hunting quest. E. Gadd also stays in his Bunker named E. Gadd's Bunker to protect himself from the ghosts.
Gadd Science Inc. has developed many inventions and tools over the years. Among which are:
- Poltergust 3000 - A high powered vacuum used to suck up ghosts, which Luigi uses
- F.L.U.D.D. - The Flash Liquidizer Ultra Dousing Device. A water cannon with Artificial Intelligence, which Mario uses.
- Magic Paintbrush - A tool Shadow Mario used to frame Mario by painting graffiti all over Isle Delfino.
- The Game Boy Horror - A parody of the "Game Boy Color", this was a machine that had a map Luigi could use to navigate the mansion that Luigi found.
- Ghost Portrificationizer - 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
- Super Poltergust 3001 - 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.
- Time Machine - Used by Princess Peach to visit the past at the beginning of Mario & Luigi: Partners in Time. It is powered by the Cobalt Star, and then the power of the time holes in the end game.
- DS Time Radar - 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.
- Hydrogush 4000 - A large water pump used in Mario & Luigi: Partners in Time. It's not portable like the F.L.U.D.D., but it does have a lot of power.
- Stuffwell - 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.
- Poltergust 4000 - The Poltergust 4000 of the vehicles used by Luigi in Mario Kart DS to race in. It is similar to the Super Poltergust 3001 and the Poltergust 3000.
- Dual Scream - Long for (DS). This object replaces the Game Boy Horror and this allows Luigi to view the floors and rooms he is at.
- Poltergust 5000 - The newest vacuum. The Poltergust 5000 can now fire Strobe Lights which is now used to stun ghosts.
- Strobulb - A green light bulb object which Luigi now uses to stun ghosts. The Strobulb can also be used to open certain things like vaults and can defeat smaller enemies in one, weak flash like Bats or Spiders.
- Pixelator - An teleporter-like object. E. Gadd uses this to transport Luigi in and out from mansions directly to or from his bunker.
- Dark-Light Device - a unique flashlight-like device that emits a rainbow light and helps Luigi see invisible objects and is the main way to help capture Boos.
- He was supposed to appear in Mario Kart DS but was replaced by R.O.B.
- He is Voiced by Kazumi Totaka who also Composes/Makes the music for most of the Mario games. He also voices Yoshi and the Villainous King Boo, as well as the boos and all of the ghosts (Except for the Polterpup)
- His name is a pun of Egad, an exclamation.