Searching for a safer habitat, the prehistoric Crood family discovers an idyllic, walled-in paradise that meets all of its needs. Unfortunately, they must also learn to live with the Bettermans -- a family that's a couple of steps above the Croods on the evolutionary ladder. As tensions between the new neighbors start to rise, a new threat soon propels both clans on an epic adventure that forces them to embrace their differences, draw strength from one another, and survive together.

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.