Moon-Boy was born into a tribe of intelligent, fur-covered, ape-like humanoids known as the "Small-Folk". The Small-Folk were hunter-gatherers that made their home in the "Valley of Flame", a region of numerous active volcanoes. Moon-Boy's connection with Devil Dinosaur began as a young boy when he came across a female dinosaur being attacked by a rival tribe known as the "Killer-Folk". The female was killed, as well as two of her three young. The third did not die however, but was transformed when the Killer-Folk attempted to burn him to death with their torches. The fire permanently scorched the young dinosaur's skin bright red. Moon-Boy cared for the orphaned creature after its ordeal and named him "Devil".