In fact, Rosato is one of only three actors (along with Robin Duke and Martin Short) to be cast members of both SCTV and SNL and the first not born in either the United States or Canada. Celebrities impersonated by Rosato on SCTV include: Lou Costello (whom he also impersonated when he was a cast member on SNL), William Conrad, Danny Thomas, Woodstock co-organizer Chip Monck, SNL cast member John Belushi, Tony Orlando, Don Ho, and Ella Fitzgerald. His characters on SNL, despite his short tenure, were memorable as well, and included Ed Asner (in character as Lou Grant), Captain Kangaroo, and U.S. Attorney General Ed Meese.
He also voiced Luigi in The Adventures of Super Mario Bros. 3 and Super Mario World.
From Wikipedia.