Vampire Dragon

shapechanger. If the vampire Dragon isn't in sunlight or running water, it can polymorph into a Dragonborn and  back into its true dragon form when ever it desires. it can also use an action to polymorph into a large cloud of mist from either form.

While in Dragonborn form 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 (3/Day). If the vampire Dragon 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 any other form, and it must reach its resting place within 2 hours or be destroyed. Once in its resting place, it reverts to its vampire Dragon 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 dragon 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.

Spider Climb. The vampire Dragon in any form can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Vampire Weaknesses. The vampire dragon has the following flaws:

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

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

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

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

Multiattack.  The vampire dragon makes 3 attacks in either form: one with its bite and two with its claws the attacks are shown  below as dragon/dragonborn to hit, reach and damage.

bite. Melee Weapon Attack: +10/9  to hit, reach 10/5 ft., one target. Hit : 17 (2d10+ 6) 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 (exclude dragonborn) slain in this way rises as an undead shadow from the corpse and acts immediately after the dragon vampire in the initiative count. the shadow is under the dragons control. ( A dragonborn slain in this way and then buried in the ground rises the following night as a vampire spawn under the vampire dragon's control.)  Note: in dragonborn form the dragon can grapple the target instead of damage with an (escape DC 18) Then bite as a bonus action till the grapple is broken. with out re-rolling to hit.

claw. Melee Weapon Attack: +10/9  to hit, reach 10/5 ft., one target. Hit : 13 (2d6+ 6) slashing damage

tail. (dragon form only) Melee Weapon Attack: +12  to hit, reach 15 ft., one target. Hit : 13 (2d6+ 6) bludgeoning damage

shadow breath (recharge 5-6). The vampire Dragon exhales shadowy fire in a 30-foot cone. Each creature must make a DC 19 Dexterity savings throw. taking 56 (16d6) neurotic damage on a failed save, or half as much damage on a successful one. A humanoid reduced to 0 hit points by this damage dies , and an undead shadow rises from the corps and acts immediately after the vampire dragon in the initiative count. The shadow is under the vampire dragon's control.

Charm. The vampire dragon targets one humanoid it can see within 30 feet of it. If the target can see the vampire dragon, the target must succeed on a DC 17 Wisdom saving throw against this magic or be charmed by the vampire dragon. The charmed target regards the vampire dragon as a trusted friend to be heeded and protected. Although the target isn't under the vampire dragon's control, it takes the vampire dragon's requests or actions in the most favorable way it can, and it is a willing target for the vampire dragon's bite attack. Each time the vampire dragon or the vampire dragon's companions do anything harmful to the target, it can repeat the saving throw, ending the effect on itself on a success. Otherwise, the effect lasts 24 hours or until the vampire dragon is destroyed, is on a different plane of existence than the target, or takes a bonus action to end the effect.

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

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

 Two other Legendary actions. These are chosen from the Dragon's origin before it became a Vampire dragon.