not that i know of, i've had it for 8 months, and he does fine..Is the frog dying?
I bought it like that from the LFS, and he said it happened when its previous owner did a water change with out dechlorinating the water..that frog doesnt look right. it looks all puffed up

I hope we are wrong, but that frog looks seriously swollen...
I don't think a cray and a frog make such good tank mates either..
Oh! So he's been like that as long as you've had him. Well, he looks otherwise healthy. I hope this cohab doesn't end badly. Feed them well and cross your fingers. And nice setup! I like the crayfish a lot.
He's actually full of air, and manages to move as if he was normal. They get along fine also..
http://www.monsterfishkeepers.com/forums/showthread.php?427654-BFF&highlight=
OMG^^ that thread is hilarious... and it's great that the cray hasn't popped your frog!!... Otherwise if there is something wrong with the frog, glad your taking good care of him..