I had a pic, but you couldn't really see him since he was backed into a corner. With a bowfront it's really hard to take good pics. He is seriously the coolest little creature I've seen...waving the anemones around warding off the hermit crabs. Very cool. They are so reclusive, though, I doubt I'll see him much. I haven't even seen him since. Hopefully, he'll be lucky and avoid the manits shrimp.
Yes, I'm sure it's a mantis. I've seen him smash his way across the rock chasing my emerald, trying to open shells, etc. I've tried to trap him but he's very skiddish - he even runs from the camera flash. The longer he's in there the more interesting he becomes. He's sort of growing on me (I'd like him if he wasn't such a killer). I totally understand why some people keep them as pets, they are amazing animals.