I found a crab in an acro mini colony I got. The other colonies had obvious white masked acropora crabs, but this one looked different so I took it out of the coral and put in the sump.
I have usually heard the hairy ones called Gorilla Crabs. Of course nowadays, with all the trade names out there, I wouldn't doubt it is called something else also. I have also always considered the hairy ones as pests and not reef safe.