It's an egg! It's a cat! It's one of the cutest things you've ever seen! Yurakoro Tamago Nyanko (loosely translated as Rock'n Roll Egg Kitties) are little egg-shaped cats that cry out when you rock them around and meow happily when you hold them. 

This sweet little gal is Momo Onemu, a.k.a. Sleepy Peach. Isn't she a doll? 

See Sleepy Peach and her friends in action!