Entrenching Mattock
Weapon (war pick), rare
You gain a +1 to attack and damage rolls with this magic weapon. This bonus increases to +3 when you use the pick to attack a creature made of earth or stone, such as an earth elemental or stone golem.
As a bonus action, you can slam the head of the pick into earth, sand, mud, or rock within 5 feet of you to create a wall of that material up to 30 feet long, 3 feet high, and 1 foot thick along that surface. The wall provides half cover to creatures behind it. The pick can’t be used this way again until the next dawn.