Rokan is a prehistoric monster from Krypton.
Background
It appeared in the episode Rokan: Enemy from Space. Rokan was a pterodactyl-like monster from Krypton. When it arrived on Earth it easily overpowered the SuperFriends, then began laying clutches of eggs that hatched into more creatures like itself. Eventually Rokan and its brood were driven off Earth with massive hunks of Kryptonite.
Powers
Rokan exhibited Kryptonian powers similar to Superman's, but at much higher magnitudes. The ones most evident were its strength, invulnerability and heat vision able to cut through Wonder Woman's Magic lasso.
Trivia
Rokan is almost certainly based on the famous movie monster, Rodan