Professor Elvin Gadd nicknamed E. Gadd (Karl Tastroff nicknamed K.Tastroff in French, referring to the french word "catastrophe") is a supporting character of the Mario series and the deuteragonist of the Luigi's Mansion series. E. Gadd also appears as a supporting character in the first two games of the Mario & Luigi series. He's an eccentric scientist specializing in ghost hunting and inventing.
He is voiced by japanese composer Kazumi Totaka, who also voices Yoshi and King Boo.
Professor E. Gadd is a small man with, for only hair, a small straight tuft in the middle of the skull. He has a tooth and always wears glasses, a blouse and brown shoes. His glasses have a spiral pattern.
Professor E. Gadd is eccentric, friendly and intelligent as he is one of the world's greatest scientists and inventors. E. Gadd is quite gibberish at times due to his accent and way of speaking.