Crab ID: TBS Hitchhiker!

[ImperialWookie]

I recently got some rock from TBS for my IM 25 Lagoon. Just curious on a few of these. I believe I have about 3 porcelain crabs, a pencil urchin (?), and an unknown crab. I found him eating another crab last night. I don’t see any black on his claws, but just checking before I start adding coral and fish! And any suggestions on catching these guys if need be?

 

[Tired]

Not a pencil urchin- they have that on their site as a purple-spined urchin.

I don't know the exact species on that crab, but it's something similar to a gorilla crab. As you can tell by the fact that it's hunting other crabs, it'll kill and eat anything it can. Remove it and put it in a sump or refugium, or humanely kill it.