WoWDB

This pet has a chance to drop from the Heart-Shaped Box which is rewarded a maximum of once a day for defeating the Crown Chemical Co. Apothecaries boss during the Love is in the Air holiday.

It looks very similar to a Disgusting Oozeling but does not debuff the player.  However, this pet has the very unique feature of eating nearby critters!  He grows in size with each critter he eats (although he seems to have a size cap).  Additionally, the critters this pet eats will found towards the guild achievements Crittergeddon & Critter Kill Squad.