Corrupted Wolf* (CR 2)

Medium Aberration
Alignment: Neutral evil
Initiative: +1 (Dex); Senses: darkvision 60 ft., low-light vision, scent (wolf), Listen +5, and Spot +3

AC: 17 (+1 Dex, +6 natural), touch 11, flat-footed 16
Hit Dice: 2d8+8 (17 hp)
Fort +7, Ref +4, Will +0
Speed: 50 ft.
Space: 5 ft./5 ft.
Base Attack +1; Grapple -4
Attack: Bite +4 melee
Full Attack: Bite +4 melee
Damage: Bite 1d8+4 plus 1 vile
Special Attacks/Actions: Trip
Abilities: Str 17, Dex 13, Con 19, Int 2, Wis 10, Cha 4
Special Qualities: Acid immunity, disruptive attack, enhanced power, fast healing 1
Feats: Weapon Finesse (bite)
Skills: Hide +2, Listen +5, Move Silently +3, and Spot +3
Advancement: 3 HD (Medium-size); 4-5 HD (Large)
Climate/Terrain: Any forest, hill, plains, and mountains
Organization: Solitary pair, or pack (7-16)
Treasure/Possessions: None

Source: Book of Vile Darkness

Disruptive Attack (Su): A corrupted wolf deals an additional 1 point of vile damage when it touches uncorrupted, living, corporeal nonoutsiders.

Trip (Ex): A corrupted wolf that hits with a bite attack can attempt to trip the opponent as a free action without making a touch attack or provoking an attack of opportunity. If the attempt fails, the foe cannot react to trip the corrupted wolf.

Fast Healing (Ex): A corrupted wolf regains lost hit points at the rate of 1 per round. Fast healing does not restore hit points lost from starvation, thirst, or suffocation, and it does not allow a corrupted wolf to regrow or reattach lost body parts.

Scent (Ex): A corrupted wolf can detect approaching enemies, sniff our hidden foes, and track by sense of smell.

Skills: A corrupted wolf receives a +4 racial bonus on Survival checks when tracking by scent.

A pack's favorite tactic is to send a few wolves against a foe's front while the rest of the pack attacks from the flanks or rear.