My baby white is really bloated?!? Is he sick?

[Lil Krystal]

My baby tree frog has bloated up over the last few days. He looks like he is going to explode, I'm really scared he is sick.
I'm not to sure if maybe he has over eaten because my other frogs looks a tad skinny. My bloated frog is still eating and his eyes look slightly closed like he is tired or something. I have had a look at some of the other bloated frog threads and its looks like a different kind of bloated. Its just his lower belly is massive

Please take a look at my photos and tell me what you think