B.C. A Special Christmas (1981)

Peter enlists his sarcastic one-legged friend Wiley to help conjure a myth based around the idea of giving. Seeing the chance to make a profit off the selflessness of others, the two caveman create a figure that develops into the first Santa Claus but are then baffled when the "myth" they've created apparently becomes real. Substituting gain for fulfillment, Peter and Wiley experience the true meaning of Christmas.