Thousands of years ago, though it is nearly impossible to say exactly how long, a human came upon a strange tree, apparently turned to stone, with a jewel stuck to its trunk like a frozen drop of golden blood. The stone spoke to him, and he plucked it, listening to its pleas in his own simple language. A spirit lived in the stone, and the spirit gave him what he most desired: power. He gained strength beyond any others in his tribe, such strength that he could tear a mastodon apart with his bare hands and outrace the fastest horse. With this power, he became a mighty ruler, for his people had seen what happened to those who would challenge him for food or women or trinkets. But for all his power, he became fat and lazy; behind his back, the tribe compared him to the great sloths that they sometimes hunted. Finally, one brave young hunter crept into the Sloth's dwelling and took the spirit gem. It spoke to him as well, and it cried for help. The spirit gave this hunter his desire as well: knowledge. And with that knowledge, he was able to free the spirit from its jeweled prison. The spirit emerged like a raging storm and returned to its world, giving the hunter its thanks. Unfortunately, the Sloth sought vengeance upon the Hunter, beginning a feud that would last for many years. Despite the Sloth's strength and abilities, the Hunter's keen mind and boundless knowledge allowed him to evade and defeat his foe time and time again. But despite his victories, the Hunter's intellect drove him farther and farther from his own people, and it seemed the Sloth would kill more and more of his loved ones each time he returned. And so it was that the Hunter sacrificed himself to stop the Sloth once and for all, destroying him utterly and taking the last piece with himself down to the bottom of a pit of tar, where he could finally be at rest.
Until today. Krypto goes digging in the La Brea Tar Pits in Los Angeles, CA, and emerges with, as you might expect, a bone. But from this oversized human femur re-emerges a villain not seen since prehistory. As the so-called Sloth starts his assault, his ancient nemesis wakes and rises from the tar. The pleistocene powerhouses plunge into pugilism, and it's up to Superman and Krypto to end this timeless struggle once and for all!
Plus, in the Second Feature, flash back to Krypto's first meeting with the futuristic super-dogs of the DogStar Patrol!