The vrykolakas has advantage on Wisdom (Perception) checks that rely on hearing or smell. Regeneration. The vrykolakas 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 vrykolakas takes radiant damage or damage from holy water, this trait doesn't function at the start of the vrykolakas's next turn. Shapechanger. The vrykolakas can use its action to polymorph into a wolf, or back into its true form, which is wolf-human hybrid. Its statistics, other than its AC, are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies. Spider Climb. The vrykolakas can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check. Stake to the Heart. The vrykolakas is destroyed if a piercing weapon made of wood is driven into its heart while it is incapacitated in its resting place