Friend or Foe?

[Crabs]

I don't want to get rid of him if he isn't hurting anything. He hitched a ride with my Pocillopora Coral ( cabbage ) a couple weeks ago. I've seen him occasionally. He's the exact color of the coral. It looked as though he was picking at the polyps. May have been cleaning around them. I'll turn him loose in the tank if I get some help here. He only hangs out in this coral

 

[Crabs]

I found info on this 1. Gorilla crab. They shouldn't look so cool. Hate to flush it but I don't have a sump. Had to flush a teddy bear crab last year. Another good looking crab