Hungry Warhammer

A hungry weapon, a creation of the daelkyr, is formed from muscle and bone. It may moan, growl, or wail, and it twists in your grip if it doesn't like you. If any creature attempts to wield this weapon while not attuned to it, it has disadvantage on attack rolls made using the weapon. Additionally, if you are attuned to this weapon when another creature tries to wield it, the weapon's hilt extrudes sharp thorns and that creature takes 1d4 points of piercing damage each turn. While attuned to and wielding this weapon, you can use a bonus action to bond to it, causing tendrils from the hilt of the weapon to burrow into your flesh. While bonded to it, you gain the following benefits:

• The weapon is bound to your hand and can't be removed from your grasp, voluntarily or involuntarily. If it's a two-handed weapon, only one of your hands is bound to the weapon.

• When you hit a creature with this weapon, you can choose to spend one Hit Die to deal additional damage with the attack, and as you do, drain the life from your foes. Roll the Hit Die and add your Constitution modifier; the attack deals extra necrotic damage equal to the result, and you regain an equal number of hit points.

You can end the weapon's bond as an action, causing the tendrils to retract so you can release the weapon. You can remain attuned to the weapon regardless of whether you're bonded to it.

Versatile: This weapon can be used with one or two hands. A damage value in parentheses appears with the property—the damage when the weapon is used with two hands to make a melee attack.

Proficiency: martial, warhammer Source: Exploring Eberron p. 230 (Third Party), Player's Handbook (2014) p. 149