Vampire Wolf

Keen Hearing and Smell. The vampire wolf has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Pack Tactics. The vampire wolf has advantage on attack rolls against a creature if at least one of the vampire wolf's allies is within 5 feet of the creature and the ally isn't incapacitated.

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

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

Vampire Weaknesses. The vampire wolf has the following flaws:

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

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

Stake to the Heart. The vampire wolf 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 vampire wolf takes 20 radiant damage when it starts its turn in sunlight. While in sunlight, it has disadvantage on attack rolls and ability checks.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (2d4 + 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 vampire wolf 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. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be knocked prone.