The prehistoric Croods family live in a particularly dangerous moment in time. Patriarch Grug, his mate Ugga, teenage daughter Eep, son Thunk, and feisty Gran gather food by day and huddle together in a cave at night. When a more evolved caveman named Guy arrives on the scene, Grug is distrustful, but it soon becomes apparent that Guy is correct about the impending destruction of their world.

Shelley is living a carefree life until a rival gets her tossed out of the Playboy Mansion. With nowhere to go, fate delivers her to the sorority girls from Zeta Alpha Zeta. Unless they can sign a new pledge class, the seven socially clueless women will lose their house to the scheming girls of Phi Iota Mu. In order to accomplish their goal, they need Shelley to teach them the ways of makeup and men; at the same time, Shelley needs some of what the Zetas have - a sense of individuality. The combination leads all the girls to learn how to stop pretending and start being themselves.