Marok is a member of a primitive tribe that lives on top of a steep-walled butte in Lost Valley. He is the brother of Yellana, and he is one of the tribe's able-bodied hunters. While on a hunting expedition, Marok and the rest of the tribe's hunters were chased into a great pit by a group of beasts and trapped by the pit's sheer walls. Staying in a cave that was also within the pit, they survived by eating the various animals that happened to stumble over the pit's edge and by drinking the water found within the cave.