Shapechanger. If the vampire isn't in sunlight or running water, it can use its action to polymorph into a Tiny bat or a Medium cloud of mist, or back into its true form.

While in bat form, the vampire can't speak, its walking speed is 5 feet, and it has a flying speed of 30 feet. Its statistics, other than its size and speed, are unchanged. Anything it is wearing transforms with it, but nothing it is carrying does. It reverts to its true form if it dies.

While in mist form, the vampire can't take any actions, speak, or manipulate objects. It is weightless, has a flying speed of 20 feet, can hover, and can enter a hostile creature's space and stop there. In addition, if air can pass through a space, the mist can do so without squeezing, and it can’t pass through water. It has advantage on Strength, Dexterity, and Constitution saving throws, and it is immune to all nonmagical damage, except the damage it takes from sunlight.

Legendary Resistance (1/Day). If the vampire fails a saving throw, it can choose to succeed instead.

Misty Escape. When it drops to 0 hit points outside its resting place, the vampire transforms into a cloud of mist (as in the Shapechanger trait) instead of falling unconscious, provided that it isn't in sunlight or running water. If it can't transform, it is destroyed.

While it has 0 hit points in mist form, it can't revert to its vampire form, and it must reach its resting place within 2 hours or be destroyed. Once in its resting place, it reverts to its vampire form. It is then paralyzed until it regains at least 1 hit point. After spending 1 hour in its resting place with 0 hit points, it regains 1 hit point.

Regeneration. The vampire regains 20 hit points at the start of its turn if it has at least 1 hit point and isn't in sunlight or running water. If the vampire takes radiant damage or damage from holy water, this trait doesn't function at the start of the vampire's next turn.

Vampire Weaknesses. The vampire has the following flaws:

Forbiddance. The vampire can't enter a residence without an invitation from one of the occupants.

Harmed by Running Water. The vampire takes 20 acid damage if it ends its turn in running water.

Stake to the Heart. If a piercing weapon made of wood is driven into the vampire's heart while the vampire is incapacitated in its resting place, the vampire is paralyzed until the stake is removed.

Sunlight Hypersensitivity. The vampire takes 20 radiant damage when it starts its turn in sunlight. While in sunlight, it has disadvantage on attack rolls and ability checks.

Spellcasting. The Vampire is a 3rd-level spellcaster (spell save DC 12, +4 to hit with spell attacks), its spellcasting ability is Wisdom, and it has the following ranger spells prepared:

1st level (3 slots): absorb elements, hunter's mark

2nd level (2 slots): pass without trace, spike growth

3rd level (1 slots): flame arrows

Multiattack. (Vampire Form Only). The vampire makes two attacks, only one of which can be a bite attack.

Ranger Bow (Vampire Form Only). Ranged Weapon Attack: +7 to hit, reach (120,300) ft., one creature. Hit: 8 (1d8 + 7) bludgeoning damage. The vampire and choose to not do damage to pin the target to the ground or other surface, Escape DC16. 

Bite. (Bat or Vampire Form Only). Melee Weapon Attack: +7 to hit, reach 5 ft., one willing creature, or a creature that is pinned by the vampire, incapacitated, or restrained. Hit: 7 (1d6 + 5) 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 the vampire 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 the vampire's control.

 Children of the Night (1/Day). The vampire magically calls 2d4 swarms of bats or rats (swarm of bats, swarm of rats), provided that the sun isn't up. While outdoors, the vampire can call 3d6 wolves (wolf) instead. The called creatures arrive in 1d4 rounds, acting as allies of the vampire and obeying its spoken commands. The beasts remain for 1 hour, until the vampire dies, or until the vampire dismisses them as a bonus action.

1st level (3 slots): absorb elements

Once each round of combat at the end of another creatures turn the vampire may take one of the two legendary actions listed below:

 Move. The vampire moves up to its speed without provoking opportunity attacks.

 Ranger Bow. Takes one attack with its bow