Combining the ideas above with some abilities of the similar aballin...
Breath Weapon (Su): Three times per day, an ahuitzotl may breath a 15-foot line of water as a standard action. This deals 1d6 points of bludgeoning damage (DC X Ref half). The water then immediately becomes a breathweird, which remains for 5d4 rounds, even if the ahuitzotl is slain or leaves the area. An ahuitzotl may have more than one breathweird present at a time. Advanced ahuitzotls have more powerful breathweirds (breathweird Hit Dice equal to 1/3 ahuitzotl's Hit Dice).
Breathweird
Small Elemental (Water)
Hit Dice: 3d8+3 (16 hp)
Speed: 30 ft. (6 squares), swim 90 ft.
AC: 17 (+1 size, +6 natural), touch 11, flat-footed 17
BAB/Grapple: +2/+0
Full Attack: Slam +5 melee (1d6+3)
Space/Reach: 5 ft./5 ft.
Special Attacks: Drown
Special Qualities: Darkvision 60 ft., elemental traits, resistance to fire X, vulnerability to cold and water effects
Saves: Fort +4, Ref +1, Will +1
Abilities: Str 14, Dex 10, Con 13, Int 4, Wis 11, Cha 11
Skills: Listen +3, Spot +3, Swim +10
Feats: Power Attack, 1 more
Drown (Ex): To use this ability, a breathweird must hit an opponent of Medium size or smaller with its slam attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and draws the victim into its fluid body. The victim is at risk of drowning (see Water Dangers in the DMG for the risks and effects of drowning). A trapped victim can attack the breathweird or make additional grapple checks to escape its grasp. The character cannot cast spells with a verbal component or use any other item or ability that requires speech. If other characters use slashing or piercing weapons to attack the breathweird while it is holding a victim, those attacks have a 25% chance of hitting the trapped character, and they do no harm to the aballin. While holding a victim, the breathweird continues to attack with its pseudopods, dealing slam damage to other characters.
Vulnerability to Cold and Water Effects (Ex): A transmute water to dust spell forces a breathweird to make a Fortitude save or perish. A lower water spell forces a breathweird to release a trapped character if it fails a Fortitude save. An attack that deals cold damage slows a breathweird (as the slow spell) for 3 rounds, with no saving throw.
Skills: Breathweirds have a +8 racial bonus on any Swim check to perform some special action or avoid a hazard and can always take 10 on Swim checks, even if distracted or endangered.