n small animal 

Perception +5; low-light vision, scent (imprecise) 30 feet

Skills Athletics +2 (+6 to Swim), Stealth +5, Survival +5

Str +0 Dex +3 Con +1 Int -4 Wis +1 Cha -2

Deep Breath The sea snake can hold its breath for about an hour.

AC  16; Fort +5, Ref +9, Will +3

HP 15

Lash Out [R] Trigger A creature within the sea snake's reach uses a move action; Effect The sea snake makes a bite Strike against the attacker.

Speed 15 feet, swim 25 feet

Melee [>] fangs +7 (agile, finesse), Damage 1d8 piercing plus sea snake venom

Sea Snake Venom (poison) Saving Throw DC 16 Fortitude; Maximum Duration 10 rounds; Stage 1 1d6 poison damage (1 round); Stage 2 1d6 poison damage and enfeebled 1 (1 round)

Bestiary 2, page 245.