When Phil invents a simple new game called ball-in-cup, everyone except Hope, can't stop playing it. But just when Hope thinks she's rid the farm of the game, she finds herself addicted to the game worst of all.

When Grug thinks his forehead looks too big in Ugga's family portrait, she strives to make the painting disappear.

When the adults exclude the kids from their adult-only cave, the kids make their own much cooler cave, soon making the adults want to switch caves.

When a freak lightning strike turns Thunk into a genius, Phil is thrilled to have someone likeminded on the farm, until the farm residents start asking Thunk for help with problems on the farm instead of him.

Tired of the farm's feud with the neighboring punch monkeys, Ugga arranges a punch summit where the Bettermans and Croods will stay in the punch monkey village to learn how to all get along.

When Phil detects a meteor is hurtling towards the farm, the Bettermans and Croods must decide how to spend their last day on earth.