The tips of it's claws which you cannot see are a dark brown color. It's been in my tank since the start (over 2 years) but it's the first time I've had a decent opportunity to get a picture. I believe it's in the Xanthidae family.
It looks to be a "gorilla crab". I have no idea what its scientific name is , only that every one who has come into contact with one has imediately removed them.
Thanks for the replies, I removed this bad ass last night. I got lucky, it ventured out on a rock near the periphery of my aquascape so I was able to just pull the entire rock out and then shake him off in my sump. I also spotted 2 other crabs last night. A gorilla crab on my red monti and some type of xanthid in my birds nest so I got those little suckers too, unfortunately the little crab in the monti lost a leg cause he wouldn't let go, but I don't have to worry about these monsters eating anything in my tank anymore.