Eel, Giant Moray
This sixteen-foot-long eel slithers through the water with uncanny grace, mouth open to display large teeth and a second set of jaws.

Giant Moray Eel (CR 5; XP 1,600)
N Large animal (aquatic)
Init +6; Senses low-light vision, scent; Perception +7
AC 19, touch 11, flat-footed 17
(+2 Dex, +8 natural, –1 size)
hp 52 (7d8+21)
Fort +8, Ref +9, Will +3
Speed swim 30 ft.
Melee bite +11 (2d6+9 plus grab)
Space 10 ft.; Reach 10 ft.
Special Attacks gnaw
Str 22, Dex 14, Con 16, Int 1, Wis 12, Cha 8
Base Atk +5; CMB +12 (+16 grapple); CMD 24 (can't be tripped)
Feats Improved Initiative, Lightning Reflexes, Skill Focus (Stealth), Weapon Focus (bite)
Skills Escape Artist +10, Perception +7, Stealth +8, Swim +14; Racial Modifiers +8 Escape Artist
Environment aquatic
Organization solitary, pair, or nest (3–6)
Treasure none
Special Abilities
Gnaw (Ex) If a giant moray begins a round with a grabbed foe, it inflicts automatic bite damage (2d6+9 points of damage). A giant moray eel possesses a second set of jaws in its throat that aid in swallowing—it can make a second bite attack (+11 attack, 1d6+3) against a foe it has already grabbed.

The moray eel is a ferocious predator, capable of holding prey in its primary jaws while a smaller set of jaws inside its throat chews away bite-sized portions.

Moray Eel Animal Companion
Starting Statistics: Size Medium; AC +5 natural armor; Speed swim 30 ft.; Attack bite (1d8); Ability Scores Str 14, Dex 16, Con 12, Int 1, Wis 12, Cha 8; Special Qualities low-light vision, grab.

7th-Level Advancement: Size Large; AC +3 natural armor; Attack bite (2d6); Ability Scores Str +8, Dex –2, Con +4; Special Qualities gnaw.