Stingray (CR 1/3)

Small Animal (Aquatic)
Alignment: Always neutral
Initiative: +3 (Dex); Senses: low-light vision, Listen +3, and Spot +3

AC: 15 (+1 size, +3 Dex, +1 natural), touch 14, flat-footed 12
Hit Dice: 1d8 (4 hp)
Fort +2, Ref +5, Will +1
Speed: Swim 30 ft.
Space: 5 ft./5 ft.
Base Attack +0; Grapple -5
Attack: Sting +4 melee
Full Attack: Sting +4 melee
Damage: Sting 1d3-1 plus poison
Special Attacks/Actions: Poison
Abilities: Str 8, Dex 17, Con 11, Int 1, Wis 12, Cha 4
Special Qualities:
Feats: Weapon Finesse
Skills: Hide +3 (+7)*, Listen +3, Spot +3, and Swim +7
Advancement: 2 HD (Small)
Climate/Terrain: Warm aquatic
Organization: Solitary, pair, or school (5-12)
Treasure/Possessions: None

Source: Stormwrack

Poison (Ex): Injury, Fortitude DC 12, nauseated 1d4 hours/1d3 Dex. The save DC is Constitution-based and includes a +2 racial bonus. A creature that makes its saving throw against the poison's initial damage is instead sickened for 1d6 rounds.

Skills: *When it is lying still along the seafloor, a stingray has a +4 racial bonus on Hide checks. A stingray has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line

Stingrays feed on crustaceans and shellfish, usually cruising just over the sea bottom. Sometimes they burrow just beneath the surface. This is when they present the greatest danger to unsuspecting creatures, who might step on or near them. A threatened stingray lashes out with its tail barb, injecting a terribly painful venom that leaves its targets virtually helpless.

Aquatic Subtype

Creatures with the aquatic subtype always have swim speeds and thus can move in water without making Swim checks. An aquatic creature can breathe underwater. It cannot also breathe air unless it has the amphibious special quality.