Trained by her parents, Eep competes in Alphafight. But when Eep learns that a human winning could upset the balance of nature, she must choose between winning to make her parents proud, and losing to protect the other animals.
Phil and Guy try to disprove the Croods' belief that leaving offerings to the fire moon will prevent bad luck, but their efforts seem to cause a series of mishaps.
Terrible at hide-and-seek, Thunk asks Gran to teach him to hide. With her training, he soon becomes her partner in crime, helping her with heists and schemes.