How did Fats Domino get his name?

Fats Domino was born Antoine Domino, Jr.

In the summer of 1947, Billy Diamond, a New Orleans bandleader, accepted an invitation to hear the young pianist perform at a backyard barbecue. Domino played well enough that Diamond asked him to join his band, the Solid Senders, at the Hideaway Club, in New Orleans. Diamond nicknamed him "Fats", because Domino reminded him of the renowned pianists Fats Waller and Fats Pichon.