Heikegani

A crab the size of a small dog scuttles forth, its shell bearing ridges and stripes forming a leering demonic face.

Source Demiurge113
Originally posted on Probing the Membrane of Science

In bays and shoals where massive battles have been fought, the seas have run red with the blood of slain soldiers. The scavenging invertebrates of these places feed well on such bounty, but their descendants are forever changed.

The resulting crabs are marked with shells that resemble the battle masks of a samurai and are haunted by their ghosts. The possessing spirits imbue their hosts with only a slight modicum of intelligence, but they react violently if their crab bodies are harmed, lashing out with spectral blades. Due to this supernatural protection, the heikegani, or samurai crabs, are rarely disturbed by either predators or fishermen, and can live hundreds of years scuttling along the coasts and seafloors.

Heikegani are somewhat more aggressive than other crabs of their size, as their supernatural abilities protect them from retribution. As such, heikegani are active predators as often as they are scavengers’ although they will rarely attack a party of humans, a lone halfling or gnome may find themselves prey. Their ghostly intelligence has no humanity to it, but they do find themselves attracted to metal items, perhaps in memory of the weapons and armor their souls once used. Heikegami lairs are decorated with scraps of iron, silver and bronze, and the occasional valuable may be found there.

Heikegani CR 1

XP 400 N Small magical beast (aquatic) Init +1; Senses darkvision 60 ft., Perception +4

DEFENSE

AC 14, touch 12, flat-footed 13 (+1 size, +1 Dexterity, +2 natural) hp 13 (2d10+2) Fort +4, Ref +4, Will +0 Defensive Abilities negative energy affinity, retributive strike

OFFENSE

Speed 30 ft., Swim 20 ft. Melee 2 claws +3 (1d3)

STATISTICS

Strength 10, Dexterity 12, Constitution 13, Intelligence 1, Wisdom 10, Charisma 13 Base Atk +2; CMB +1; CMD 12 (20 vs. trip) Feats Combat Reflexes Skills Perception +4, Stealth +9, Swim +8 SQ amphibious

ECOLOGY

Environment temperate costal Organization solitary, pair, gang (3-6) or cast (4-24) Treasure incidental

SPECIAL ABILITIES

Retributive Strike (Su) Whenever a heikegani is struck with a melee weapon, a touch attack or a natural weapon, it can make an attack of opportunity against the creature that made the successful attack. This attack deals 1d8 points of damage and is considered to be slashing, magic and force for the purposes of bypassing damage reduction. Weapons with exceptional reach do not endanger their wielder in this way.