Legion of Doom was formed by Christopher Reeve with the mission to stop Hack-Man from getting the law passed to stop his eating of baby fetuses. These fetus's stem-cells keep Christopher fit by reversing the effects of his paralysis.
The Legion of Doom is made up of super villains seen throughout the series. The group is a parody of the DC Comics' own Legion of Doom.
Christopher Reeve is an actor and activist in stem-cell research for persons with physical disabilities. He is also the founder of the Legion of Doom in the episode, "Krazy Kripples".
Saddam Hussein is the former dictator of Iraq and a former resident of Hell. He is a current resident of Heaven. He was last seen in the episode, "It's Christmas in Canada", where he was the deposed Prime Minister of Canada.
Butters Stotch's alter-ego Professor Chaos and his sidekick General Disarray were initially members of the Legion of Doom, however, they quit after realizing how sensitive the subject matter was, claiming that they should "stay out of this one." He was previously seen in the episode "My Future Self n' Me".
Dr. Victor von Doom is a comic-book villain created by Stan Lee.
Dr. Octopus is a major antagonist in the Spider-Man series of comics.
Solomon Grundy, who was originally a Mafia member from Prohibition times who was killed in a shootout, then later transformed into a revenant when revived by dark magic. He had also become much stupider, but this was due to decay ruining his memories of his former life. When he mentioned he "...died on Saturday", the other villains associated him with the Mother Goose rhyme of Solomon Grundy, and as such was commissioned with that name.