Crab ID?
 

This crab hitchhiked in one one of my corals, when he arrived he was mostly white with little purple on the ends of his claws. His coral has since died and he resides mostly in my live rock. He has turned completely purple.
This is a picture of his "skin" after he molted. It is not a picture of the crab, just his shell.
Does anyone know what he is?

I had one of these. Everytime he molted he got bigger and blacker. I would watch him.

With those claws I would throw him in a fuge or sump....:biggrin:

Looks like he's got those 'hairy' legs and hairy = bad. Catch him and put him in the sump.

Unfortunately I don't have a sump, he's in a 26g tank. Any ideas what he is? What is he going to do if I don't get rid of him?

Thanks.

i'd say put him in a specimen box for now until you find a more permanent solution

Yea, permanent like a mantis tank.

I came across this site and thought it might be of some help in determining what you have.
http://reefkeeping.com/issues/2003-12/rs/index.php