bite attack

Bite (Bat or Vampire Form Only). Melee Weapon Attack: dex+prof to hit, reach 5 ft., one willing creature, or a creature that is grappled by you, incapacitated, or restrained. Hit: (1d6 + dex) piercing damage plus (3d6)necrotic damage. The target's hit point maximum is reduced by an amount equal to the necrotic damage taken, and you regain hit points equal to that amount. The reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point