What are these crabs?

Does anyone know what these little hairy crabs are? They don't have shells like little blue-legs. They are just regular crabs but brown and hairy. I must have gotten it s a hitchhiker on some live rock. My husband came home last night and found it on top of my beloved bubble coral chowing down. He even ate the skeleton part of my bubble coral, I guess while trying to eat the last bit of bubble flesh. Anyway, I am going to catch him and take him back to the store. If my bubble doesn't come back in a week or so, I guess I will have to pronounce it dead. Erggghhhh

 

There is all sorts of little brown hairy crabs and most of them are bad. Got a pic?

 

Sounds like a xanthid crab. I think some call it a rock crab. Sounds like you already know that you don't want it!