Lycanthropy

You carry a soul of a beast within yourself. You gain the following effects:

• You can change your form into a werewolf once per day and you are forced to change your form on nights with full moon.
• You gain resistance to Bludgeoning, Piercing, and Slashing damage from nonmagical attacks but you are vulnerable to silvered weapons.
• You have advantage on Wisdom (Perception) checks that rely on hearing or smell.
• You gain darkvision up to 60ft or extend your sight by 30ft if you already have darkvision.
• You gain disease immunity.

This feat can only be chosen if a character is somehow contracted with Lycanthropy (being bitten, performing a Lycanthropy ritual, one of the parents having Lycanthropy, etc.).