I'm a Monkey's Uncle(1948)

The Stooges are cavemen in the Stone Age who must fight for their mates Aggie, Maggie and Baggie.

Set in the stone age, the stooges are cavemen who must have various misadventures hunting, gathering, and otherwise coping with prehistoric life. When some other cavemen threaten to take their women ("Aggie", "Maggie", and "Baggy"), the boys fight them off with a catapulting tree branch that shoots rocks and eggs.