Snake, Whip (CR 2)

Medium Animal
Alignment: Always neutral
Initiative: +3 (Dex); Senses: low-light vision, scent, Listen +7, and Spot +7

AC: 16 (+3 Dex, +3 natural), touch 13, flat-footed 13
Hit Dice: 3d8+6 (19 hp)
Fort +4, Ref +6, Will +2
Speed: 20 ft., climb 20 ft., swim 20 ft.
Space: 5 ft./5 ft.
Base Attack +2; Grapple +5
Attack: Bite +5 melee
Full Attack: Bite +5 melee
Damage: Bite 1d3+4
Special Attacks/Actions: Coil slam 1d4 (see text), constrict 1d6+4, improved grab
Abilities: Str 17, Dex 17, Con 13, Int 1, Wis 12, Cha 2
Special Qualities:
Feats: Alertness; Toughness
Skills: Balance +11, Climb +14, Hide +10, Listen +7, Spot +7, and Swim +11
Advancement: 4-6 HD (Medium); 7-9 HD (Large)
Climate/Terrain: Temperate marshes
Organization: Solitary
Treasure/Possessions: None

Source: Serpent Kingdoms

Coil Slam (Ex): A whipsnake can whip its body against an opponent (+5 melee), dealing 1d4 points of damage on a successful hit. In addition, the target must make a DC 12 Reflex save to escape the coils. Failure means the opponent lands prone in its square, and the whipsnake automatically establishes a hold on it and can constrict as if it had made a successful grapple check.

Constrict (Ex): On a successful grapple check, a whipsnake deals 1d6+4 points of damage.

Improved Grab (Ex): To use this ability, a whipsnake must hit with its bite attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and can constrict.

Skills: A snake has a +4 racial bonus on Hide, Listen, and Spot cheeks and a +8 racial bonus on Balance and Climb checks. A snake can always choose to take 10 on a Climb check, even if rushed or threatened. A snake uses either its Strength modifier or its Dexterity modifier for Climb checks, whichever is higher.

A whipsnake 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.

Whipsnakes usually lurk on sturdy tree branches, ready to drop or slither onto creatures passing underneath. However, they have also been known to lie on the ground, stretched across a trail amid fallen tree branches, waiting to coil around the legs of creatures using the path and trip them. A whipsnake's first attack is always a coil slam.