Undead

You are an Undead creature. You are resistant to necrotic damage. You also need 1 ration of blood every 5 days or your body begins to cease functioning. On the 5th day without blood, the Vampire is unable to heal and takes 1d20 of damage every hour and rolls disadvantage on everything. If the Vampire drops to 0 hit points from this, they are paralyzed until force fed blood. Then they regain 1d20 hit points taken from loss of blood and no longer roll disadvantage.

Sunlight Hypersensitivity

Because of the corpse a vampire resides in, sunlight burns any skin it comes into contact with. A Vampire takes 20 radiant damage when it starts its turn in sunlight. While in sunlight, it has disadvantage on attack rolls and ability checks.

Stake to the Heart

If a piercing weapon made of wood is driven into the Vampires heart, the Vampire begins to desiccate and is paralyzed until the stake is removed. However, if this happens when a Vampire is at 0 hit points, they spontaneously combust and are destroyed. The soul of the Vampire leaves the burning corpse and seeks its final resting place. It may be captured and used as a component to a spell.

Bite

At 1st level, you can use your sharp fangs to inflict damage. One willing creature, or a creature that is grappled by the Vampire, incapacitated, or restrained. Hit: 1d6+DEX piercing damage plus 1d6 necrotic damage. The amount of bite damage increases as you gain levels. 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, also satisfying their need for blood. The reduction lasts until the target finishes a long rest. A humanoid slain after being bitten, and then buried in the ground will rise the following night as a Vampire Spawn. The necrotic damage increase at 5th, 7th, 12th, 15th, and 19th levels, by 1d6 (5th to 2d6, 7th to 3d6, 12th to 4d6, 15th to 5d6, and 19th to 6d6)

Spider Climb

Once per long rest, the Vampire can cast Spider Climb on themselves.

Hypnotic Gaze

Starting at 3rd level, your enchanting gaze can magically enthrall another creature. As an action, choose one creature that you can see within 5 feet of you. If the target can see or hear you, it must succeed on a Wisdom saving throw against your spell save DC or be charmed by you until the end of your next turn. The charmed creature's speed drops to 0, and the creature is incapacitated and visibly dazed.

On subsequent turns, you can use your action to maintain this effect, extending its duration until the end of your next turn. However, the effect ends if you move more than 5 feet away from the creature, if the creature can neither see nor hear you, or if the creature takes damage.

Once the effect ends, or if the creature succeeds on its initial saving throw against this effect, you can't use this feature on that creature again until you finish a long rest.

Children of the Night

At 5th level, once per long rest, as an action, the vampire may call on a swarm of bats or rats, if the sun isn't up. The summoned creatures arrive in 1d4 rounds, acting as allies, and obeying spoken commands. They remain until the vampire dies, an hour passes, or as a bonus action, they are dismissed. At 9th level, the vampire may summon 2 swarms, of either bats or rats.

Regeneration

When you reach 7th level, at the beginning of each of your turns, if the vampire hasn’t taken damage from holy water, or radiant damage, or doesn’t start their turn in running water or sunlight, the vampire can heal half their level plus their CON modifier (rounded up). Regeneration only works, if the vampire has at least 1 HP.