Dire Horse (CR 4)

Large Animal
Alignment: Always neutral
Initiative: +1 (Dex); Senses: low-light vision, scent, Listen +8, and Spot +8

AC: 16 (-1 size, +1 Dex, +6 natural); touch 10, flat-footed 15
Hit Dice: 8d8+48 (84 hp)
Fort +12, Ref +7, Will +8
Speed: 60 ft.
Space: 10 ft./5 ft.
Base Attack +6; Grapple +16
Attack: Hoof +11 melee
Full Attack: 2 hooves +11 melee and bite +6 melee
Damage: Hoof 1d6+6, bite 1d4+3
Special Attacks/Actions:
Abilities: Str 22, Dex 13, Con 22, Int 2, Wis 15, Cha 11
Special Qualities:
Feats: Endurance; Run; Toughness
Skills: Listen +8 and Spot +8
Advancement: 9-16 HD (Large); 17-24 HD (Huge)
Climate/Terrain: Any land
Organization: Solitary or herd (6-30)
Treasure/Possessions: None

Source: Monster Manual II

Dire animals are fierce fighters that prefer melee combat. They are territorial, attacking anything that enters their territory or threatens their lairs.

A dire horse usually lashes out with its hooves and follows up with a bite attack. It can fight

Scent (Ex): A dire horse can detect approaching enemies, sniff out hidden foes, and track by sense of smell.

Saving Throws: A dire animal has all good saves.

while carrying a rider, but the rider cannot also attack unless he or she succeeds at a Ride check (DC 10).

Carrying Capacity: A light load for a dire horse is up to 519 pounds; a medium load is 520-1,038 pounds; and a heavy load is 1,039-1,557 pounds. A dire horse can drag 7,785 pounds.