Moon-Boy was born into a tribe of
ape-like humanoids known as the Small-Folk 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 survived, but was badly burnt, turning his skin red. Moon-Boy cared for the orphaned creature after its ordeal and named him Devil. Ostracized from his tribe because of his association with Devil, Moon-Boy and Devil become wanderers. Devil and Moon-Boy's wanderings take them to distant times and worlds. After several trips to the modern era of
Earth-616 via magic, time travel, and teleportation by mutants, the two settle in the
Savage Land of Earth-616. After the
Roxxon Energy Corporation invades the Savage Land,
Ka-Zar recruits Moon-Boy and Devil Dinosaur to fight them. Later, the
Heroes for Hire take Moon-Boy to New York City, place him into
S.H.I.E.L.D. custody, and separate him from Devil. This leads
Stegron to attack S.H.I.E.L.D. bases in an attempt to rescue him. After learning of Stegron's motivations, the heroes return Moon-Boy and Devil Dinosaur to the Savage Land. Moon-Boy and Devil Dinosaur frighten off a pair of Killer Folk to reclaim the Nightstone, which the Killer Folk worshiped and had killed many Small Folk over. Devil Dinosaur chases away the Killer Folk while Moon-Boy claims the Nightstone, intending to hide it far away from the Killer Folk's reach. A band of Killer Folk emerge from the trees and attack Moon-Boy, beating him relentlessly to reclaim the Nightstone. The Nightstone disappears due to a vortex opened by
Lunella Lafayette, which the Killer Folk leave through in search of the Nightstone. After Moon-Boy dies from his injuries, Devil Dinosaur travels into the vortex to avenge him. Some time later, Devil and Moon Girl make use of a time machine to save Moon-Boy moments before his death. ==Powers and abilities==