I'm terrible at naming Pets.
I had a dog, I named Him Barkley after the Dog on Sesame Street. (I was 5)
I had a duck, He was Duckie.
I had a Snake, He was Snakey.
I've had a few Betta fish. They have all been Mr. Betta.
BTW... I vote for fluffy. Its already what I think of when I think of the little bug.