Alex Toth had submitted a different roster for the Legion of Doom that included villains from the rogues galleries of both Batman and Captain Marvel, assuming the latter would be in the show. In the original proposal the Legion Of Doom consisted of: Dr. Sivanna, Abra-Kadabra, Captain Cold, Cheetah, Gorilla Grodd, Heatwave, The Joker, Mr. Atom, Oggar, The Penguin, Poison Ivy, Sinestro, and Beautia Sivanna (the Dr's daughter). Filmation Associates held the rights to Captain Marvel and related characters (featured in "Shazam!" (1974)) and most of the Batman villains were being used on
The New Adventures of Batman (1977) (although HB and Filmation shared rights to Batman and Robin), so the group had to be retooled. The Captain Marvel villains were dropped and the Batman villains replaced, as were most of the Flash villains.