Episode 5 - Dark Magic and A Twisted Fate
After Gabbie gets captured, the Black Knight ties her up in Round Room. He then brings in the Caveman and ties him up as well, saying that the Caveman is an escaped exhibit. He helps the group by first finding the Light of Annwn. When the Black Knight reappears, the Caveman distracts him and both disappear into the night.
Episode 9 - Prehistoric Evil
The Caveman and his Cavewoman have stolen an egg from Dinosaurs. They find a statue of the Cursed God and dig it up. His girlfriend gets stabbed in the neck and he carries her away to bury her. He then as the remaining guests help him finish his paintings, put bones on her grave, and get animal totems. When they get all three and put them, along with a raptor egg, on a pedestal, the Cursed God Statue is revealed. The guests grab the key and run to the Collector's Vault. Meanwhile, the caveman touches the statue and a green light enters him, having an unknown effect.