The biggest star in Animal House is, without a doubt, John Belushi. He was already one of the most famous comedic actors in the country due to his success on Saturday Night Live. However, Animal House was his very first starring role, and he was joined by other young actors who were on their way up, like Karen Allen, Stephen Furst, Tim Matheson, Tom Hulce, Bruce McGill, and, of course, Kevin Bacon, in his first-ever movie role.