Originally Posted by GuidoNGR
Yeah Donkey Mong appears under Mal's/Entrance to Ore Chasm, but he will only appear if King Mong isn't there when you come in the area and you cleared everyone out around his area.
Found Donkey Mong about twenty minutes after I posted about it. Still no Chubby though. I'll chill out on looking for now since I have another playthrough. Hopefully I'll run into him.