You gain advantage on Hearing and smell(Perception) Checks

You gain expertise in Perception

You have immunities against: Bludgeoning, Piercing, and Slashing From Nonmagical Attacks Not Made With Silvered Weapons

You gain the Bite attack and are considered proficient: Melee Weapon Attack, one target, 1d8+Strength piercing damage. If the target is a humanoid, it must succeed on a DC 10 + Constitution Modifier, Constitution Saving Throw or be cursed with werewolf lycanthropy.

Werewolf lycanthropy: 
If cursed the character needs to choose to resist or give in to the curse.

Resisting:

Normal conditions(every day):
You need to roll a d20+con mod rolling higher then 10 - con mod to not lose to the curse. If succeeded, you win from the curse, taking no damage. If failed, you fail to win from the curse, making your character hungry and Chaotic Evil. Attacking everyone it sees. 

Normal conditions(Combat):
After getting more than 25 damage. You get angry and the curse comes into play. The other characters will be warned that something is wrong.
You need to roll a d20+con mod rolling higher then 10 - con mod to not lose to the curse. If succeeded, you win from the curse, taking no damage. If failed, you fail to win from the curse, making your character hungry and Chaotic Evil. Attacking everyone it sees. 

Moonlit conditions(During full moon):
You need to roll a d20+con mod rolling higher then 10 + con mod to not lose to the curse. If succeeded, you win from the curse, taking no damage. If failed, you fail to win from the curse, making your character hungry and Chaotic Evil. Attacking everyone it sees. 

Moonlit conditions(Combat during full moon):
After getting more than 10 damage. You get angry and the curse comes into play. The other characters will be warned that something is wrong.
You need to roll a d20 mod rolling higher then 10 + con mod to not lose to the curse. If succeeded, you win from the curse, 1d6 damage. If failed, you fail to win from the curse, making your character hungry and Chaotic Evil. Attacking everyone it can see. If trying to resist during your rampage you do this again untill you win against the curse.

Other players, can help you with an animal check or nature check Throwing above 15 will turn the + con mod into a - con mod. Throwing under currently does nothing.(Cannot thing of anything without making it too OP.)

If you choose to give in you lose controll of your character, untill a friendly uses a Remove Curse on you or kill you off. 

The curse can be lifted with Remove Curse.

You gain the Claw attack and are considered proficient: Melee Weapon Attack, one target, 2d4+Strength slashing damage.

 Your ability scores each increase by 1.

Lycanthrope

Your strength score increases by 1.

Humans reach adulthood in their late teens and live less than a century.

 Humans tend toward no particular alignment. The best and the worst are found among them.

Humans vary widely in height and build, from barely 5 feet to well over 6 feet tall. Regardless of your position in that range, your size is Medium.

Your base walking speed is 40 feet.

You can speak, read, and write Common and one extra language of your choice. Humans typically learn the languages of other peoples they deal with, including obscure dialects. They are fond of sprinkling their speech with words borrowed from other tongues: Orc curses, Elvish musical expressions, Dwarvish military phrases, and so on.