The Cliff Men lived in Kira, the Cave World of Mongo. When Flash was made King of the Caves they had not been conquered, so he had to conquer it himself. The Cliff Men were the first tribe Flash encountered. He defeated Zug, Chief of the Cliff Men, and was accepted as King by the tribe. Zug agreed to help Flash conquer his Kingdom. The Monster Komok lived near the Cliff Men, but was killed by the Hawkmen.