Mego World's Greatest Super-Heroes (WGSH) toys were produced between 1972 and 1982. There were nine waves of action figures: The 1st Wave (Superman, Batman, Robin and Aquaman) debuted in 1972. The 2nd Wave (Tarzan, Captain America, Spider-Man and Shazam!) followed in 1973. By the end of 1974, Mego had issued the Super-Gals (Wonder Woman, Supergirl, Batgirl and Catwoman), the Super-Foes (Penguin, Joker, Riddler and Mr. Mxyzptlk) and the exclusive Secret Identity outfits (Clark Kent, Bruce Wayne, Dick Grayson and Peter Parker). Mego introduced the 3rd Wave , (Green Arrow, Green Goblin, Lizard, Falcon, Iron Man and Hulk), along with the U.S. Fist-Fighters (Batman, Robin, Joker and Riddler) in 1975. The 4th Wave, the final "official" offering of WGSH figures (Thor and Conan along with Mr. Fantastic, Thing, Human Torch and Invisible Girl from the Fantastic Four), was introduced in 1976. 1977 brought the final wave of 8 inch Super-Heroes (Isis along with Kid Flash, Aqualad, Speedy and Wonder Girl from the Teen Titans), though none of the culminating characters were branded as Mego WGSH. Mego formally cancelled the line at the end of 1982.