Eric is that critter on the new A.Loripes colony if so it's probably just a commensal, but it's hard to see it...maybe you can find it here... http://www.chucksaddiction.com/coral_crabs.html
I hate to do it because I love inverts but, upon close inspection of the coral, it looks like the little bugger is eating polyps . Not much damaage yet, but he's gonna have to go.