National Lampoon's Homo Erectus synopsis
Ishbo (Adam Rifkin) is a caveman living in the prehistoric age who thinks there's more to life than hunting and gathering. He tries to better the lives of those in his tribe by inventing things like spoons and the toothbrush, which leave everyone, including his parents (David Carradine, Talia Shire), unimpressed. He also has a thing for cavewoman Fardart (Ali Larter), but she only has eyes for his brother Thudnik (Hayes MacArthur). Can Ishbo prove his worth when a rival clan attacks?