I think in some of the pics he was puffing himself up on purpose as he got...significantly "fatter" when I picked him up, kind of like a balloon. The second time I picked him up to put him back in the tank, I heard what sounded like a deep breath and he got puffed up again. He kind of seemed to deflate a little after being put back into his tank and not touched for a few minutes. I do try not touch or handle him if I don't absolutely have to as I've read it's generally stressful for frogs to be handled and he very obviously does not like it (tries to get away, puffs up, struggles, so far he hasn't tried to bite though).

It's neat to see him come out and, save for the first week, he doesn't seem to bury himself completely so I can usually see his head and part of his back so that's always nice. Currently he's made his burrow on the side with the UTH. I figure having a warm side has to be nice as, in his tiny critter keeper prior, he didn't have anything like that.