The Purple Cavemen are a tribe lead by Ukan.
During the events of Yor, the Hunter from the Future (1983)
While a village celebration is going on, a group of Purple Cavemen start killing the village sentries. They then attack the villagers celebrating. Ukan tells his people to kill all of the men of the village. The next day, while Yor, the Hunter and Ka-Laa are walking, they are ambushed by the Purple Cavemen. Yor tells Ka-Laa to run away and Yor is knocked unconscious. Ukan takes Yor's medallion and Ka-Laa is taken hostage when she tries to save Yor. Yor is then thrown from the cliff. Ka-Laa is brought before Ukan and Ukan fights three of his tribesmen for the right to own Ka-Laa. Yor uses the body of the Beast of the Night to glide into the cave and kicks Ukan in the face, knocking him unconscious. He grabs Ka-Laa and his medallion back and he and he and Ka-Laa flee. They cross a bridge over the bones of people and after crossing it, Yor throws it over the edge. They come to an area of water and Yor opens the dam holding it back. Ukan jumps on a ridge and watches as his tribe of Purple Cavemen are washed away. As Ka-Laa and Roa are fighting, Ukan and a couple of Purple Cavemen appear and Ka-Laa calls for Yor. Yor and Pag rush to help her and Roa is hit in the head with a club. Yor and Pag kill the Purple Cavemen and Yor kills Ukan by smashing a rock on his head.