Comics

• In the comic books, the "Legion of Super Heroes" made their debut in 1958's "Adventure Comics" No. 247. Eventually they would star in their own book, which would become revamped and rebooted over the years by different creators.
  
  

Creation

• The "Legion" cartoon was created as part of Cartoon Network's desire to have an animated Superman series that would coincide with the 2006 film "Superman Returns." However, Cartoon Network declined to order the series, so "Legion of Super Heroes" ended up on the CW Kids' WB cartoon lineup.
  
  

Season 3

• Though the show only lasted two seasons, the producers had planned a third prior to cancellation. The third season would have featured Brainiac 5 redeeming himself after turning evil in season two, as well as introducing characters like Wildfire and Shadow Lass.
  
  

The Comic Book Adaptation

• To promote the show, DC Comics also published a tie-in comic, which lasted 20 issues and continued publication for a year after the cartoon's cancellation.
  
  

Other Cartoons

• "Legion of Super Heroes" was not the first appearance of the Legion in cartoon form. They first appeared in the 1998 "Superman" episode "New Kids in Town" to thwart a scheme by the supervillain Brainiac to kill young Clark Kent before becoming Superman. They also feature in the 2006 "Justice League Unlimited" episode "Far From Home," where they enlist Supergirl to battle a group of villains called The Fatal Five.