Ashworm (CR 2)

Large Magical Beast
Alignment: Always neutral
Initiative: +0; Senses: tremorsense 60 ft., Spot +3, and listen +6

AC: 14 (-1 size, +5 natural), touch 9, flat-footed 14
Hit Dice: 3d10+9 (25 hp)
Fort +4, Ref +5, Will +4
Speed: 30 ft., burrow 30 ft., climb 5 ft.
Space: 10 ft./5 ft.
Base Attack +3; Grapple +12
Attack: Sting +7 melee
Full Attack: Sting +7 melee
Damage: Sting 1d6+7 plus poison
Special Attacks/Actions: Poison
Abilities: Str 21, Dex 10, Con 17, Int 1, Wis 13, Cha 6
Special Qualities: Evasive diver
Feats: Alertness; Lightning Reflexes
Skills: Climb +16, Spot +3, and listen +6
Advancement: 4-6 HD (large); 6-9 HD (Huge)
Climate/Terrain: Warm deserts or plains
Organization: Solitary, cluster (2-4), or herd (6-30)
Treasure/Possessions: None

Source: Sandstorm

Poison (Ex): Injury, Fortitude DC 14, initial and secondary damage 2d6 Str. The save DC is Constitution-based.

Evasive Diver (Ex): In areas of sand (not packed earth or stone), the ashworm feels more secure because of its evasive diver ability. If the ashworm makes a successful Reflex saving throw against an attack that normally deals half damage on a successful save, the ashworm instead manages to instantly dive below the protective sand or earth and takes no damage.

An ashworm's rider might be swept from the ashworm's back unless it makes a DC 15 Reflex save when the ashworm dives below the sand. If the rider fails this save, it is swept from the ashworm's back. Particularly skilled riders, such as ashworm dragoons with the sand rider ability, go along for the dive and also take no damage from the effect that prompted the ashworm's Reflex save.

Ashworms hunt prey from beneath the sand, then rise to confront their targets. In battle, an ashworm forms into a coil, stinging anything in reach.