Dawn of the Croods
The Good Surprise / Night Mare On Eep Street
S2 E4:
When Ugga's new surprise attack fails, and she comes home in a bad mood, Thunk tries to cure it by finding a happy surprise for his mom. / Eep stays up all night to see the mysterious and rare Night Mare (a horse with a rainbow mane) when she's teased for thinking they're not real.