Wannyaa

Wannyaa, also known as Baumiao, is a babysitter pet from Planet Otto, who is entrusted to take care of Luu, and is a cat-like alien who can transform into all sorts of human beings, often a blond-haired man (dubbed Mitarashi Dango) who was actually once the subject of Mikan's affection, and all forms of animals and objects. He develops a passionate liking for dumplings, and often writes about the events of the progressing day in his computerized nanny diary. Wannyaa often does all the cooking and cleaning in the house.

(Source: Wikipedia)