What is short for Moogi?

This is our pet dog, Moogi ... as sweet and playful as a puppy, though she's the oldest member in the family (8x7 y.o). Sweet Potato calls her "Gee". I guess "moo.." is reserved for the cow. And you would never guess what he chooses to call Auntie Wati ... "Da-da". I am totally baffled by that one, haven't the faintest clue what gave him that idea.