In 1981, Post Cereals (now part of Kraft) ran a promotion with the aid of DC Comics and Hanna-Barbera encouraging kids to create their own super villains to battle the Super Friends. To be fair, there was also a Create-a-Hero contest, too.
VintageTVCommercials uploaded this ad, featuring Superman (Danny Dark), Wonder Woman (Shannon Farnon), Batman (Olan Soule), & Robin (Casey Kasem). Long-time H-B standby John Stephenson is the announcer, subbing for narrator Bill Woodson:
Sad to say, the contest didn't get very far. I can't recall if the winning entries in either contest were ever used.