Other voice over roles included Uncle Arthur on Babar (1989–1991), Quicksilver and Arkon on X-Men (1992–1996), Luke Talbot on Monster Force (1994), the title character on Free Willy (1994–1995), and Lefty on John Callahan's Quads!

Haddad's voice roles include Quads, Mythic Warriors, Cyberchase, The Adventures of Super Mario Bros. 3, Super Mario World, Little Bear, The Magic School Bus, RoboRoach, Pearlie, Franny's Feet, The Adventures of Tintin and Rupert.

[3] Haddad's role in Resident Evil 2 led to him becoming an "icon" among the game's fanbase according to Gamasutra.

His hobbies included film editing (often with videos of his dog) and assisting with actor demos.

He detailed his personal and financial struggles in a complementing Facebook post, which revealed he had obsessive–compulsive disorder (OCD) for most of his life.