There are two kinds of these crabs a***: blunt-toothed (Hirsch's Crab) mixed with ringed crab; the ones with blue spots on their feet are ringed crab, as shown in the picture below.

The others are blunt-toothed (钝齿蟳) (shown below).

Blunt-toothed hairy sea-crab and ringed hairy sea-crab both belong to the general family of pike crabs, Pikeidae, subfamily of short-shelled crabs, genus Crab, and both are edible. Also, by the way, that snail you have is probably a stick cone snail.