Brine Vampire Spawn

Amphibious. The vampire can breathe air and water.

Vampire Weakness. The vampire has these weaknesses:

Dry Earth. The vampire has Disadvantage on D20 Tests while standing on terrain that isn’t a liquid.
Forbiddance. The vampire can’t enter a residence without an invitation from an occupant.
Stake to the Heart. If a weapon that deals Piercing damage is driven into the vampire’s heart while the vampire has the Incapacitated condition in its resting place, the vampire has the Paralyzed condition until the weapon is removed.
Sunlight. The vampire takes 20 Radiant damage if it starts its turn in sunlight. While in sunlight, it has Disadvantage on attack rolls and ability checks.

Water Walk. The vampire can move across any liquid surface—such as water, acid, mud, snow, quicksand, or lava—as if it were harmless solid ground, although it can still take damage from heat if crossing lava. The vampire can submerge into the liquid if it chooses and doesn’t automatically rise to the surface.

Multiattack. The vampire makes two Claw attacks and uses Bite.

Claw. Melee Attack Roll: +6, reach 5 ft. Hit: 8 (2d4 + 3) Slashing damage. If the target is a Medium or smaller creature, it has the Grappled condition (escape DC 13) from one of two claws. While Grappled, the target is Suffocating while underwater unless it can breathe water.

Bite. Constitution Saving Throw: DC 14, one creature within 5 feet that is willing or that has the Grappled, Incapacitated, or Restrained condition. Failure: 5 (1d4 + 3) Piercing damage plus 10 (3d6) Necrotic damage. The target’s Hit Point maximum decreases by an amount equal to the Necrotic damage taken, and the vampire regains Hit Points equal to that amount.

Deathless Agility. The vampire takes the Dash or Disengage action.