Fallout Boy is a fictional character in the universe of the animated television show The Simpsons. In the series, Fallout Boy first appeared in a 1950s Radioactive Man film serial shown at a comic book convention in the episode "Three Men and a Comic Book". However, unlike many Simpsons characters, he has only made a handful of appearances since. While Radioactive Man is a broad parody of many superheros, most obviously containing elements of Batman and Superman (and the comic incorporates an origin story similar to Marvel's The Hulk), among others, Fallout Boy is mainly a parody of Robin (with his costume, references as being the 'young ward' of Radioactive Man, and his younger age and sidekick status) with elements of Spider-Man (his fictional comic book origin, for example).

In The Simpsons episode Radioactive Man, a Radioactive Man movie was set to be made in Springfield. A casting call for Fallout Boy was sent out to the children of Springfield. Bart Simpson, a huge fan of Radioactive Man, tried out for the role but lost it to his friend Milhouse Van Houten because he was an inch too short. After Milhouse snaps from the pressure of being a movie star, Mickey Rooney steps in to try and fill the role. The attempt fails and the film is scrapped.

Bongo Comics

Additionally, Fallout Boy also appears in a real-life comic book titled Radioactive Man, published by Bongo Comics (a comic created in part by Matt Groening, the creator of The Simpsons) . In these comic books, Fallout Boy's real name is Rod Runtledge, he has a brother named Dodd Runtledge, and they live in Zenith City. Rod is a high school nerd living with his aunt, Aunt June, an obvious reference to Spider-Man's alter ego, Peter Parker, who lives with his Aunt May.

Trivia

Fallout Boy was the inspiration to the name of the pop punk band, Fall Out Boy.