Vampire Potbelly Goblin

Nimble Escape. The Vampire Potbelly Goblin can take the Disengage or Hide action as a bonus action on each of its turns.

Regeneration. The VPG regains 10 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 VPG takes radiant damage or damage from holy water, this trait doesn't function at the start of the VPG's next turn.

Spider Climb. The VPG can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Vampire Potbelly Goblin Weaknesses. The VPG has the following flaws:

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

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

Stake to the Heart. The VPG is destroyed if a piercing weapon made of wood is driven into its heart while it is incapacitated in its resting place.

Sunlight Hypersensitivity. The VPG 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 VPG makes two attacks, only one of which can be a bite attack.

Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 8 (2d4 + 3) slashing damage. Instead of dealing damage, the VPG can grapple the target (escape DC 13).

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one willing creature, or a creature that is grappled by any VPG, incapacitated, or restrained. Hit: 6 (1d6 + 3) piercing damage plus 7 (2d6) necrotic damage. The target's hit point maximum is reduced by an amount equal to the necrotic damage taken, and the VPG 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.

Potbelly Drum Roll.  The VPG may drum on its belly to summon a swarm of rats if its health drops down below 10 HP