Dire Boar (CR 4)

Large Animal
Alignment: Always neutral
Initiative: +0; Senses: low-light vision, scent, Listen +8, and Spot +8


AC: 15 (-1 size, +6 natural), touch 9, flat-footed 15
Hit Dice: 7d8+21 (52 hp)
Fort +8, Ref +5, Will +8
Speed: 40 ft.
Space: 10 ft./5 ft.
Base Attack +5; Grapple +17
Attack: Gore +12 melee
Full Attack: Gore +12 melee
Damage: Gore 1d8+12
Special Attacks/Actions: Ferocity
Abilities: Str 27, Dex 10, Con 17, Int 2, Wis 13, Cha 8
Special Qualities:
Feats: Alertness; Endurance; Iron Will
Skills: Listen +8 and Spot +8
Advancement: 8-16 HD (Large); 17-21 HD (Huge)
Climate/Terrain: Temperate forest
Organization: Solitary or herd (5-8)
Treasure: none

Source: Monster Manual

Combat

A dire boar charges its opponents, trying to rip them open with its tusks.

Ferocity (Ex): A dire boar is such a tenacious combatant that it continues to fight without penalty even while disabled or dying (see page 129 in the Player's Handbook).