Stony Grasp

Warlock Invocation
Level: Lesser, 4th lv, Sorcerer/wizard 3
Components: V, S
Casting Time: 1 standard action
Range: 60 feet
Duration: 1 round/lv
Saving Throw: None
Spell Resistance: Yes

By thrusting your arm downward, you complete the casting of the spell. Nearby, a roughly formed arm about the size of a human erupts from the ground and grasps at the air.
This spell functions like earthen grasp, except as noted here.
The stony arm can appear from any natural surface, including unworked rock, earth, mud, grass, or sand. The stone arm has AC 18, hardness 8, and 4 hit points per caster level.

(Complete Arcane, Page 134)