Skull Hammer (5e Equipment)
From D&D Wiki
Weapon (maul), rare
This magic maul bears a huge head resembling a skull, and strikes from it feel supernaturally forceful. When attacking with this weapon, you add your proficiency bonus to damage rolls instead of attack rolls. Attacks with this weapon deal double damage to objects and structures.
Shockwave (Requires Attunement). As an action, you can make one special kind of melee attack using the skull hammer. If you hit, damage is dealt as normal. Regardless of whether or not you hit your target, however, the attack emits a shockwave of magical force. The target and all creatures within 5 feet of the target, other than you, take 1d4 force damage.
Soaring Strike (Requires Attunement). When you use the Attack action on your turn and hit a Small or smaller creature with the skull hammer, you can send that creature flying. It must succeed on a DC 15 Strength saving throw or be thrown 10 feet directly away from you and land prone.