Superfriends: Rest in Peace Super Friends : Season 3 Episode 30
TV-G ABC 1h 00m
Aired: December 16th, 1978 @ 12:00 AM EST on ABC
The Legion of Doom unearths a crystal called "Noxium", created by one time member Dr. Natas. The Crystal can kill all of the Super Friends using emulations of their weakness such as Kryptonite, Yellow Power or lethal energy only to find out too late they were in hiding and had really killed off their clones.
