easter egg
A colored egg, usually hidden by the Easter bunny, or a chocolate egg with a filling. Also, a secret inside a game or movie that's just for fun and doesn't help you win.
My little brother found a chocolate egg and ate it so fast, he got a tummy ache.
I found a secret in the game and felt like I was part of the club.
The Easter bunny left eggs, but I was too lazy to find them.