These eel-like creatures seem oddly different, almost as if one can see emotions on their faces, and not good ones.

Sarrenel (CR 3; XP 800)
NE Small magical beast (aquatic)
Init +3; Senses see in darkness; Perception +2
AC 17, touch 14, flat-footed 14
(+3 Dex, +3 natural, +1 size)
hp 25 (3d10+9)
Fort +6, Ref +6, Will +0
Immune electricity; SR 14
Speed 15 ft., swim 30 ft.
Melee bite +7 (1d4+1 plus 1d4 electricity)
Special Attacks electricity, feeding frenzy
Str 12, Dex 16, Con 16, Int 5, Wis 8, Cha 6
Base Atk +3; CMB +3; CMD 16 (can’t be tripped)
Feats Skill Focus (Perception), Weapon Finesse
Skills Acrobatics +9, Perception +2, Swim +9
SQ amphibious
Environment aquatic
Organization gang (2-5) or swarm (6-20)
Treasure none
Special Abilities
Electricity (Ex) The creature’s bite deals 1d4 points of electrical damage in addition to the damage resulting from the bite itself. In addition, any creature making direct physical contact with the sarrenel also sustains 1d4 points of electrical damage per round of exposure.
Feeding Frenzy (Ex) The scent of fresh blood incites the cruel predators’ aggressive instincts. If the creatures deal 10 or more points of non electrical damage in a single round, all of the sarrenels receive a morale bonus to attack and damage rolls on the following round equal to +1 per 10 points of damage dealt in the previous round.

Generations of specialized breeding and magical intervention changed placid aquatic creatures into amphibious killing machines. Despite several hundred years of remarkable evolution and humanoid interference, the creature’s anatomical features remain relatively intact with a few notable exceptions. At first glance, the sarrenel seems virtually indistinguishable from a normal eel. A closer inspection belies its true nature. In total darkness, the beast’s eyes emit a dull, yellow glow, revealing its brutal feral quality. Naturally aquatic, the sarrenel also possesses four small flippers that empower it to venture onto dry land. Sarrenels retain their ancestors’ dark coloration, enhancing their ability to hide within shallow murky waters. Sarrenels grow to a maximum length of 3 feet with an average diameter of 6 inches. Despite their evolutionary advances, sarrenels are incapable of speech.

Savage and primordial, the aggressive beasts attack foes with unabated fury, viciously tearing chunks of flesh from their victims. Sarrenels rely upon stealth to approach their target and then attack foes en masse in a manner reminiscent of a swarm of angry hornets. They never retreat regardless of the circumstances.

On Porphyra
Another example of living weapons created for the NewGod Wars, sarrenels were engineered by undine and sylph elemental-kin to deny safe access to water by Deist troops, even to infest city sewers and pristine lakes. It is rumored that there are magical devices specifically keyed to control sarennels, probably lost in the retreat of Elementalist forces.