As an actor, Don Sullivan occupies a strange position in the history of cinema. The movies in which he starred were never (and still aren't) taken seriously by the critics -- pictures like The Giant Gila Monster, Teenage Zombies, and The Rebel Set appeal to a certain kind of genre film buff, of a sort not much represented in journalism or scholarship until the 1990s, more than 30 years after their release. Yet Sullivan had starring roles in these and other, similar low-budget productions of the era -- in other words, he left behind a body of work that can be observed and evaluated and, on examination, isn't all that bad. That he wasn't a great actor is clear, but performing in a certain kind of role, as a sort of slightly nerdy hero, he was one of the most convincing young leading men of his generation -- not James Dean or Marlon Brando, to be sure, but far superior to the likes of Tony McCoy (the lead in Edward D. Wood Jr.'s Bride of the Monster). Sullivan's earliest officially credited acting role was in an episode of The Adventures of Wild Bill Hickock that aired in late 1956, when he would have been 18 years old. The following year, he made his big-screen debut in a leading role in Edward Dein's B-Western Seven Guns to Mesa, made for Allied Artists. It was two years before Sullivan was seen onscreen again, but 1959 was a banner year for the young actor, as he played starring roles in four feature-film releases and a bit part in a fifth. The Giant Gila Monster was the best of his films and offered Sullivan the meatiest role, as the flawed but well-meaning hero, Chase Winstead, a part that not only allowed him to show off what acting skills he had but also his abilities as a singer and composer -- Sullivan composed the three numbers, "I Ain't Made That Way," "The Mushroom Song," and "My Baby She Rocks," that his character sang in the film. Nobody thought much of the movie, and no one's performance in it was going to get them an offer from the Royal Shakespeare Company, but looked at today the movie does have a certain innocent appeal that's nicely embodied in Sullivan's work. In Teenage Zombies, he played a similar slightly innocent and naive hero, while in The Monster of Piedras Blancas, Sullivan portrayed a somewhat more worldly and bold heroic figure. He also played a small role in Universal's bizarre vampire/Western amalgam Curse of the Undead. The Rebel Set, also released in 1959, placed Sullivan into a crime-caper setting in which none of the players looked very appealing but everyone performed adequately. In 1961, Sullivan made one last foray into feature films with a leading role in Hugo Haas' fascinating film- (or non-film) within-a-film drama Paradise Alley. He disappeared from movies and television beyond that point, although Sullivan has achieved a certain enduring popularity in both media, among B-movie buffs, for his 1959 output -- at least three of his features, The Monster of Piedras Blancas, The Rebel Set, and The Giant Gila Monster, have become the subjects of installments of Mystery Science Theater 3000, and even those who deride the production values of all three movies admit to a certain appreciation of Sullivan's performance in The Giant Gila Monster.