The best place I’ve found to get the Chubby/Tubby midget was Boombringer at Sawtooth. If your farming Sawtooth make sure you go around. I’ve had one there a couple of times. Will look for my old post on the previous forum.
Got it: It was the Loot Midget Goliath, super rare chap. Scroll down as my original pic is gone.
Edit: Sorry, half asleep. This is about chubby not loot midgets, but worth seeing anyway