Advice? Finally caught him!

I have been trying to catch this little guy for a couple months now. He has out smarted, until tonight. This time I waited until right after the light went out and started looking. Got my red flashlight out and shined it in the tank and there he was sitting on top of the rock like he owned the joint. I was able to reach in a pluck him off the rock and he never saw it coming. Can anyone identify him? I suspected he was a stone or gorilla crab. I saw him sitting on top of my hammer coral one day and although I never saw him do it, I suspected he was the one nibbling on my candy cane. He is about 1.5 or 2 inches wide