What do I do for my hermit crab he is out of its shell
It could be two things:
He could have molted, which is shedding his former skin. It would look like a dead crab but it's just the skin, and he is actually in a new shell.
If there weren't any other shells that he could switch into, he could have died looking for one.
Hermit crabs need at least 4 different sized shells per crab in the tank to change into, it helps clean out their gills and helps them to grow healthily.
Get him a bigger shell... but I hope he's not dead.
I suggest get him a new shell
IS HE DEAD