Brute Force

A thin gent in formal wear, amid a club or party, reads a book about primitive man after he's ignored by a pretty lady. We see the book enacted: Weakhands loses his girlfriend to Bruteforce, but chances upon a design for a weapon to vanquish his rival and win her back. His tribe sees this and sets him up as their leader. With the club, he fends off various creatures (a winged lizard, a snake, a dinosaur) and a rival tribe led by Monkeywalk. The women even manage to repel an attack. But the rival tribe discovers the secret of the club themselves, and capture the women. Weakhands, sitting in despair, chances upon a new weapon: the bow and arrow.