Trigger A creature that the giant crab can see targets the crab with an attack
Effect The giant crab scuttles to the side and gains a +2 circumstance bonus to AC against the triggering attack. After the attack resolves, the crab can Stride up to its speed in a straight line as part of the reaction.
AC 17; Fort +6, Ref +9, Will +7
HP 16; Resistances physical 2 (except bludgeoning)
Vulnerable to Prone
If a creature critically succeeds at a check to Trip the giant crab, the crab is flipped over onto its back in addition to the usual effects. A giant crab flipped onto its back has a particularly hard time defending itself; instead of taking the normal -2 circumstance penalty to AC for being Off-Guard, it takes a -4 circumstance penalty to AC.
Speed 25 feet, swim 15 feet
Melee Claw +10 (unarmed), Damage 1d6+3 slashing plus Grab
Constrict
1d4+3 bludgeoning damage, DC 17 basic Fortitude save
The monster deals the listed amount of damage to any number of creatures Grabbed or Restrained by it. Each of those creatures can attempt a basic Fortitude save with the listed DC.
Grab
Requirements The monster's last action was a successful Strike that lists Grab in its damage entry, or the monster has a creature Grabbed or Restrained
Effect If used after a Strike, the monster attempts to Grapple the creature using the body part it attacked with. This attempt neither applies nor counts toward the creature's multiple attack penalty.
The monster can instead use Grab and choose one creature it's grabbing or restraining with an appendage that has Grab to automatically extend that condition to the end of the monster's next turn.