Earthgrab

Earth Grab
This Weapon stores the implacable strength of the earth deep within. When this weapon is used, this power occasionally comes to the surface, calling on the earth to erupt from the ground and hold an enemy in place.
 * 4% chance of Earth Grab encasement
 * Reflex save DC of 35 (As of U12 Freedom of Movement no longer prevents from Earth Grab)
 * Has a duration of 6 seconds, no recurring saves
 * Deals a small amount of bludgeoning damage every 2 seconds (3 tics total)
 * Target is immobilized, and helpless (monsters take +50% damage from all sources.)

Found on:
 * Alchemical Crafting tier 1
 * Ratkiller (level 16 tier 3 and later)
 * Green Steel Weapons tier 3

Earth Grab Guard
This item stores the implacable strength of the earth deep within. When the wearer is successfully attacked in melee, this power occasionally comes to the surface, calling on the earth to erupt from the ground and hold an enemy in place
 * 4% chance of Earth Grab encasement on getting hit by melee attacks
 * Reflex save DC of 35 (As of U12 Freedom of Movement no longer prevents players from being Earth Grabbed)
 * Has a duration of 6 seconds, no recurring saves
 * Deals a small amount of bludgeoning damage every 2 seconds (3 tics total)
 * Target is immobilized, and helpless (monsters take +50% damage from all sources.)

Found on:
 * Alchemical Crafting tier 1
 * Dragontouched Armor with Sovereign Rune
 * Epic Stonemeld Plate Armor
 * Green Steel Accessory tier 3
 * Rock Boots (level 16 and later)