OH! You DON'T want to be grabbed by that big claw!! I know this from experience.
We have had quite a few of these little darlings over the years and they can be a lot of fun. We had a large one, Tank, who loved to play legos. He would pinch a small base and the boys would build on to it. He is the one who grabbed me on the palm. it took me a couple minutes to get him loose. Running them under warm water did the trick. When you hold them, extend your hand out tight, bending your fingers back away from your palm as far as you can. They can't pinch you that way. Or...give them something to hold onto.
When they molt they need to get wet. This is when they are most vulnerable and can be torn to bits by the other crabs. If one is burrowing, you might want to isolate it until it changes shell and molts.
Have fun, they have faces, uh, eyes and antenae only a mother could love.