Each stage comes with is own perks and disadvantages, and each transformation eventually takes its toll.

Class Skills Available

Keen Hearing and Smell (Stage 1-5): The werewolf has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Moon Rage (Stage 1-5): Every full moon the werewolf makes a forced transformation into the Winter Wolf. A WIS 14 saving throw must be made to retain control. Full transormation on full moon creates damage immunity to non magical bludgeoning, slashing, and piercing.

Wolf Perception (Stage 1-5): The werewolf has proficiency in Perception.

Wolf Immunity (Stage 1): Immunity to all poisons.

Silver Weakness (Stage 1-5): Attacks against the werewolf have advantage, plus 1d10 bonus damage on hit. Future stage healing nullified for 1 turn if hit.

Class Skills Available

Multiattack (Humanoid or Hybrid Form Only):The werewolf makes two attacks: one with its bite and one with its claws or weapon.

Bite (Stage 2-5): Melee Weapon Attack: Reach 5 ft., one target. Hit: (2d6 + 4) piercing damage. If the target is a creature, it must succeed on a DC 14 Strength saving throw or be knocked prone. DC 14 Constitution saving throw or be infected when moon raged.

Claws (Stage 2-5): Melee Weapon Attack: Reach 5 ft., one creature. Hit: (2d4 + 2) slashing damage.

Wolf Immunity (Stage 2): Immunity to all poisons and 1d4+CON healing per turn.

Terrifying Form (Stage 2): Enemies in sight must make a WIS 12 saving throw or be frightened. 

Class Skills Not Available

Tough Hide (Stage 3): Bonus 1 AC, Damage resistance to bludgeoning, piercing, and slashing.

Wolf Leap (Stage 3-5): Doubled Jump distance.

Wolf Immunity (Stage 3): Immunity to all poisons and 1d6+CON healing per turn.

Terrifying Form (Stage 3): Enemies in sight must make a WIS 13 saving throw or be frightened. 

Class Skills Not Available

Tough Hide (Stage 4): Bonus 2 AC, Damage resistance to bludgeoning, piercing, and slashing.

Quadrepetal Movement (Stage 4-5): Weapons are dropped and movement speed is increased to 50.

Beastial Might (4-5): +2 bonus to strength.

Wolf Immunity (Stage 4): Immunity to all poisons and 1d8+CON healing per turn.

Terrifying Form (Stage 4): Enemies in sight must make a WIS 14 saving throw or be frightened.

Class Skills Not Available

Tough Hide (Stage 5): Bonus 2 AC, Damage Resistance to bludgeoning, piercing, and slashing.

Pack Tactics (Stage 5): The wolf has advantage on an Attack roll against a creature if at least one of the wolf's allies is within 5 ft. of the creature and the ally isn't Incapacitated.

Snow Camouflage (Stage 5): The wolf has advantage on Dexterity (Stealth) checks made to hide in snowy terrain.

Wolf Immunity (Stage 4): Immunity to all poisons and 1d10+CON healing per turn.

Terrifying Form (Stage 2): Enemies in sight must make a WIS 15 saving throw or be frightened.

Cold Breath (Stage 5, Recharge 5-6): The wolf exhales a blast of freezing wind in a 15-foot cone. Each creature in that area must make a DC 12 Dexterity saving throw, taking 18 (4d8) cold damage on a failed save, or half as much damage on a successful one.

Carriers of the Winter Wolfs curse are immune to the cold.

Thanks to your wolf blood, you have superior vision in dark and dim Conditions. You can see in dim light within 60 feet of you as if it were bright light, and in Darkness as if it were dim light. You can't discern color in Darkness, only shades of gray.

The werewolves unarmed attacks do magic damage now.

 Your ability scores each increase 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 30 feet.

You can speak, read, and write Common, Giant, and one extra language of your choice. Werwolves 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.