As nouns the difference between crab and scorpions
is that
crab is a crustacean of the infraorder brachyura, having five pairs of legs, the foremost of which are in the form of claws, and a carapace or
crab can be the crab apple or wild apple or
crab can be the tree species , native of south america or
crab can be short for carabiner while
scorpions is .
As a verb crab
is to fish for crabs or
crab can be (obsolete) to irritate, make surly or sour.