Just an update. My pacman seems back to normal now. He has moved now and is burrowed back into the substrate and is looking better. I am going to keep a close eye on him tonight and tomorrow. So maybe he was just regurgitating something.

If anyone still has some insight on this I would appreciate it, I have never dealt with this before and I am just guessing that this is what happened from reading stuff online- and that can't always be reliable.