Lycanthropy

Bitten by werewolf, drank werewolf blood or venom, or born to werewolf parents.

A character who gains this feat somehow becomes a werewolf therianthrope. How the character gets this lycanthropy can be worked out with the DM and the Player but some options include being cursed, bitten by a werewolf, or drinking the blood of a werewolf.   As a newly turned werewolf before the full moon you gain the following traits.  

• Your Strength becomes 15. If it was already higher you gain a +1 bonus to your Strength Score.
• You gain proficiency in the perception skill
• You gain darkvision out to 60 feet.

On your first full moon after being afflicted with Lycanthropy you will transform into hybrid form with no control over your actions and bloodlust going on to try and kill and eat anyone and anything you can find.
While in hybrid or wolf forms you gain the following traits    

• You gain claws which are natural melee weapons you are proficient in. These one-handed finesse weapons deal 2d4 slashing damage on a hit.
• You gain teeth which are a natural melee weapon you are proficient in and can make bite attacks with. If you have a feature such as multiattack that lets you attack multiple times you may only use this bite attack once per action. A creature hit with this attack takes 1d8 piercing damage and must make a Constitution Saving Throw or be afflicted with lycanthropy. The DC of this saving throw equals 8 + your proficiency bonus + your consitution modifier.
• You gain a howl which you can use to create an audible sound up to 3 miles away. All werewolves who hear this howl within 3 miles know the exact direction and distance it came from.
• You gain the keen hearing and smell trait which grants you advantage on perception checks which rely on hearing and smell.
• You gain immunity to bludgeoning, piercing, and slashing damage from nonmagical sources.
• You gain a +1 bonus to Armour Class.
• You gain a 10 foot bonus to your movement speed
• You cannot speak in animal form

    You lose all of those benefits when you unshift from hybrid form.   Once you have properly practiced lycanthropy and trained your features you may begin to draw on your hybrid features in your true form or shift forms as a bonus action. This practice however can take months or even years especially without proper training from another werewolf.