Steeder (CR 4)

Large Magical Beast
Alignment: Always neutral
Initiative: +1 (Dex); Senses: scent, Listen +3, and Spot +11

AC: 14 (-1 size, +1 Dex, +4 natural), touch 10, flat-footed 13
Hit Dice: 6d10+18 (51 hp)
Fort +8, Ref +6, Will +5
Speed: 40 ft., climb 20 ft.
Space: 10 ft./5 ft.
Base Attack +6; Grapple +5
Attack: Bite +9 melee
Full Attack: Bite +9 melee
Damage: 1d8+6 plus poison
Special Attacks/Actions: Poison
Abilities: Str 18, Dex 12, Con 17, Int 5, Wis 13, Cha 6
Special Qualities: Invisibility
Feats: Improved Bull Rush; Iron Will; Power Attack
Skills: Hide +4, Listen +3, Move Silently +7, and Spot +11
Advancement: 6-10 HD (Large)
Climate/Terrain: Any underground
Organization: Solitary or nest (2-5)
Treasure/Possessions: None

Source: Races of Faerûn

Invisibility (Su): Once per day, the steeder can make itself invisible, as the invisibility spell from a 12th-level caster.

Poison (Ex): Bite, Fortitude save (DC 16); initial and secondary damage 1d6 temporary Strength.

Scent: Detect opponents within 30 feet. Exact location is not revealed, unless within 5 feet.

Skills: Steeders receive a +4 racial bonus on Hide and Move Silently checks and a +8 racial bonus on Spot checks.

In a fight, steeders like to surprise their opponents and charge, injecting poison into big foes and bull-rushing smaller enemies against walls or off cliffs. They are equally at home on a cavern's floor, walls, or ceiling, so they can confound their opponents by climbing to a good tactical position.

Steeders often fight with gray dwarves on their backs. Both the gray dwarf rider and the steeder can turn themselves invisible, so they often attack from surprise.