Darkhunter’s spear

You summon a spear made of a single bone from an ancient beast and tipped with a blade of volcanic glass. You gain a +1 bonus to attack and damage rolls made with this magic weapon, which deals an extra 2d6 piercing damage against A medium or large aberration type creature, Or an extra 4d6 piercing damage against creatures of the aberration type that are huge or larger. Once per turn, when you hit a regenerating creature with an attack using this magic spear, you can attempt to disable its ability to regenerate. When you do so, the creature must succeed on a Constitution saving throw against your spell DC, or its regeneration doesn't function at the start of its next turn.

Duration: 3 attacks or up to 1 minute.