n medium animal 

Perception +3; no vision, tremorsense 30 feet

Skills Athletics +4

Str +2 Dex -1 Con +3 Int -5 Wis +1 Cha -5

AC  13; Fort +9, Ref +3, Will +3

HP 18

Regurgitation [R] Trigger The giant maggot takes damage; Effect The giant maggot regurgitates its rancid, foul meal. All creatures in a 5-foot emanation must succeed at a DC 16 Fortitude save or become sickened 1 (or sickened 2 on a critical failure). The giant maggot can't use Regurgitation again until it spends at least an hour feeding on a corpse.

Speed 10 feet

Melee [>] mandibles +6, Damage 1d8+2 piercing plus Grab

Gnaw Flesh [>] Requirements The giant maggot has Grabbed a creature; Effect The giant maggot deals 1d8+2 slashing damage to the grabbed creature as it chews the creature's flesh (DC 19 basic Reflex save).

Bestiary 2, page 120.