Yes all crabs hide. You can try a crab trap which is just a water bottle with the top cut off and inverted. Just tie a string to it and pull it out when the crab goes in. You can also try a shot glass trap. If you know where its at why not just pick up the rock and scoop him up with a net?
Bringing this back up as I think I have one too. It has gotten huge, looks like a spider with its legs. Keeps turning up my torches. I can't catch it either. It started off red and is now brown.
Is that how yours was/is?