uncommon ce huge aberration amphibious swarm 

Perception +18; greater darkvision, tremorsense (imprecise) 30 feet

Skills Athletics +20

Str +4 Dex +6 Con +5 Int -4 Wis +1 Cha -2

AC  28; Fort +17, Ref +24, Will +13

HP 210; Immunities precision, swarm mind

Speed 35 feet, burrow 35 feet

Burrowing Agony [>] The swarm deals 4d6 piercing damage and 2d4 persistent bleed damage to every creature in its space (DC 29 basic Reflex save). The first time per round that a creature is affected by an aukashungi swarm's Burrowing Agony, the creature is also exposed to expeditious evolution.

Expeditious Evolution (curse, disease) This affliction can't be reduced below stage 1, nor the damage from it healed, until successfully treated with remove curse or a similar effect; the affliction can then be removed as normal for a disease. Saving Throw DC 27 Fortitude; Stage 1 The aukashungi swarm chooses two of the victim's ability modifiers. (such as Strength and Charisma)

Extinction Curse #4: Siege of the Dinosaurs, page 50.