Skeletal Warbeast (CR 4)

Large Undead
Alignment: Always neutral evil
Initiative: +7 (+3 Dex, +4 Improved Initiative); Senses: darkvision 60 ft., Spot +5, and listen +6

AC: 14 (-1 size, +3 Dex, +2 natural), touch 12, flat-footed 11
Hit Dice: 8d12 (52 hp); DR: 5/bludgeoning
Fort +4, Ref +5, Will +6
Speed: 50 ft.
Space: 10 ft./5 ft.
Base Attack +4; Grapple +13
Attack: Gore +8 melee
Full Attack: Gore +8 melee and 2 hooves +3 melee
Damage: Gore 1d8+5, 2 hooves 1d6+2
Special Attacks/Actions: Powerful charge
Abilities: Str 20, Dex 16, Con -, Int 2, Wis 10, Cha 1
Special Qualities: immunity to cold, pass without trace, undead traits
Feats: Great Fortitude, Improved Initiative, Run
Skills: Jump +17, Spot +5, and listen +6
Advancement: 9-16 HD (Large)
Climate/Terrain: Any
Organization: Any
Treasure/Possessions: None

Source: Heroes of Battle

Powerful Charge (Ex): A skeletal warbeast deals 4d6+10 points of damage when it hits with an attack after a charge.

Pass Without Trace (Su): A skeletal warbeast can move through any type of terrain without leaving any tracks or scent. Tracking a skeletal warbeast is impossible by non-magical means.

Skills: Skeletal warbeasts have a +4 racial bonus on Jump checks.

Carrying Capacity: A light load for a skeletal warbeast is up to 400 pounds; a medium load, 401-800 pounds; and a heavy load, 801-1,200 pounds. A skeletal warbeast can drag 6,000 pounds.

A skeletal warbeast can fight while carrying a rider, but the rider cannot also attack unless he or she succeeds on a Ride check. Skeletal warbeasts begin most encounters by charging enemies with their heads lowered.

An intelligent rider will avoid head-to-head fights, opting instead to use the steed's great speed to stay out of melee and force enemies to use ranged weapons (which are nearly useless against the steed's skeletal body).

Created by an evil necromancer for an undead army, a skeletal warbeast has the body of a large warhorse attached to the skull of an oryx (a plains-dwelling antelope with two long, straight horns).

Skeletal warbeasts are more than just animated horned warhorses, though. The great magic used to create these steeds allows them to retain much of the abilities they had in life - speed, strength, and knowledge - while gaining the ferocity of the undead and the supernatural ability to leave no tracks behind.