Professor E. Gadd

Professor Elvin Gadd is an accomplished scientist specialising in paranormal research. He owns and operates the company Gadd Science, Incorporated. When he was but a youngster, he lived on the foothills of Thwomp Volcano, where he had a lab and studied Thwomps and the volcano itself. However, his lab was destroyed by Thwomps in an eruption, and he relocated to an affordable lab at the edge of Boo Woods to focus on paranormal research. Years later, he met Luigi when saving him from a ghost in a haunted mansion near his residence, and the two became good friends/acquaintances/business partners. Some time after passively helping Luigi rescue his brother Mario from King Boo, E. Gadd decided to relocate again to Evershade Valley due to its friendly ghosts being easier to study than the hostile kind (and passively helped Luigi save Mario from King Boo at least two more times).

What E. Gadd is actually known for are his various inventions, his most famous being the Poltergust. Other inventions of his include the Flash Liquidizer Ultra Dousing Device (F.L.U.D.D. for short), the Magic Paintbrush (now owned by Bowser Jr.), the Pixelator, the Ghost Portrificationizer, the Hydrogush 4000, Robo Mario, Gooigi, Stuffwell, a time machine, etc. He's also quite the coffee drinker and is the founder and owner of Starbeans Cafe in the Beanbean Kingdom.