Stacian

At a glance:
Sooner or later, everything is crab.

Speed: 30ft. (walk) / 30ft. (swim)
Size: Medium
Ether: Flow.
(+1 Mana Regeneration.)
Darkvision: Yes (60ft.)

Special Features:
Carcinite.

Choose: increase your Toughness by 1 or Armor by 2.
You have two additional pincer limbs. They may be used to lift, grasp, pull, or carry, but are not dexterous enough for most other tasks. Once per Round as a Free Action, you may use them to Crush an object they are holding or creature you are Grappling, inflicting Bludgeoning damage equal to your Character Level.
You can breathe, speak, and otherwise operate underwater without hinderance. You suffer no penalty using melee weapons underwater.