To answer some of the questions: My best guess was skin shed I saw. There was no odd behavior. The last thing he ate were nightcrawler pieces the evening before he died.

Stress? I do have dogs that bark frequently that they can hear and may sometimes see. Each enclosure is generally covered on three sides completely, with the "front" side covered about 3" up due to some are at a lower height such that one of my dogs (around 20 pounds each) could see them. He was in a position where he looked like he may have been trying to get out (propped up against the side), so I guess it is possible one of my dogs saw him moving around and gave him a heart attack. Generally my dogs do not bother the frogs.

I wish a dedicated frog room would work for me as that would solve the possible dog issue, but it doesn't work for me. All my frogs are in my main living area, but I am basically the only traffic, except for my dogs, with occasional visitors. The frogs seem to be ok so far.

Edits: I got him around the first week of July, at around 1 1/4 inches. He and my fantasy frog came from Big Apple Herps. He was my first brown colored pacman frog.