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Medium undead (lizardfolk, shapechanger), lawful evil
Saving Throws Dex +9, Wis +8, Cha +9
Shapechanger. If Malack isn't in sunlight or running water, he can use his action to polymorph into a Tiny bat or a Medium cloud of mist, or back into his true form.
Legendary Resistance (3/Day). If Malack fails a saving throw, he can choose to succeed instead.
Misty Escape. When he drops to 0 hit points outside his resting place, Malack transforms into a cloud of mist (as in the Shapechanger trait) instead of falling unconscious, provided that he isn't in sunlight or running water. If he can't transform, he is destroyed.
Regeneration. Malack regains 20 hit points at the start of his turn if he has at least 1 hit point and isn't in sun light or running water. If Malack takes radiant damage or damage from holy water, this trait doesn't function at the start of Malack's next turn.
Cantrips (at will): chill touch, guidance, inflict minor wounds, radiant lance, thaumaturgy
Spider Climb. Malack can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Vampire Weaknesses. Malack has the following flaws:
Multiattack (Vampire Form Only). Malack makes two attacks, only one of which can be a bite attack.
Unarmed Strike (Vampire Form Only). Melee Weapon Attack: +9 to hit, reach 5 ft., one creature. Hit: 8 (1d8 + 4) bludgeoning damage. Instead of dealing damage, Malack can grapple the target (escape DC 18).
Bite (Bat or Vampire Form Only). Melee Weapon Attack: +9 to hit, reach 5 ft., one willing creature, or a creature that is grappled by Malack, incapacitated, or restrained. Hit: 7 (1d6 + 4) piercing damage plus 10 (3d6) necrotic damage. The target's hit point maximum is reduced by an amount equal to the necrotic damage taken, and Malack regains 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 maximum to 0. A humanoid slain in this way and then buried in the ground rises the following night as a vampire spawn under Malack's control.
Charm. Malack targets one humanoid it can see within 30 feet of it. If the target can see Malack, the target must succeed on a DC 17 Wisdom saving throw against this magic or be charmed by Malack. The charmed target regards Malack as a trusted friend to be heeded and protected. Although the target isn't under Malack's control, it takes Malack's requests or actions in the most favorable way it can, and it is a willing target for Malack's bite attack.
Children of the Night (1/Day). Malack magically calls 2d4 swarms of bats or rats, provided that the sun isn't up. While outdoors, Malack can call 3d6 wolves instead. The called creatures arrive in 1d4 rounds, acting as allies of Malack and obeying its spoken commands. The beasts remain for 1 hour, until Malack dies, or until Malack dismisses them as a bonus action.
The vampire can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The vampire regains spent legendary actions at the start of its turn.
Move. Malack moves up to his speed without provoking opportunity attacks.