an exoskeleton +5 armor it is extremely hard to break but must be molted every 3-4 months but can be molted on command every week. after each molt the crab will gain 1 inch in size. it takes up to 4 days (roll d4) and during this time the crab is extremely vulnerable. a crab must also molt after they gain a level, when they molt due to level gain it only takes an hour to regrow and the crab gains up to 8 inches (roll d8)

the double antennae adds 5 to perception checks but none to passive perception  

after two molts a crab will regrow all lost limbs to half size and then after a third molt the limb will be back to its proper size.

can breath in land and in water

crab loses some mobility with each leg sheltered but gains 1 defense defense point for every leg sheltered, if you shelter while moving you will slide at the same speed bouncing off objects. the legs that are unsheltered are vulnerable. 

you are able to burrow into the ground, you gain 10 speed if you are in sand or loose dirt 

you can attack with your claws

when you make a succesful attack the enemy takes 1 crab damage. if they take 10 crab damage they become a crab.