Arkham Werewolf

Shapechanger. The werewolf can use its action to polymorph into a wolf-humanoid hybrid, or back into its true form, which is a Dragonborn. Its statistics, other than its AC, are the same in each form. Any equipment it is wearing or carrying is transformed. It reverts to its true form if it dies.

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

Silver resistance. The werewolf has immunity to nonmagical attacks that aren't silvered. It also gains 1D12 + 10 HP at the start of its turn if it wasnt attacked with silver last round. 

Change Shape. The dragonborn magically polymorphs into the Arkham Werewolf, or back into its true form. It reverts to its true form if it dies. Any equipment it is wearing or carrying is absorbed or borne by the new form (the dragonborns's choice).

Multiattack. (Dragonborn or Hybrid Form). The werewolf makes two attacks: two with its bite (Dragonborn form) or one with its bite and two with its claws (hybrid form).

Anti-Matter Claws. (Hybrid Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 12 (2d8 + 2) force damage. This damage cannot be ignored or reduced; additionally, items and armor hit with it are permanently damaged. 

Bite (Dragonborn or Hybrid Form). Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 6 (1d8 + 2) piercing damage. If the target is a humanoid, it must succeed on a DC 12 Constitution saving throw or be cursed with werewolf lycanthropy.

Breath Attack (Dragonborn Form Only) (Recharge 5–6). The dragonborn uses one of the following breath weapons:

Sub-Zero Shock Breath. The dragonborn exhales an icy and electric blast in a 30-foot cone. Each creature in that area must make a DC 12 Constitution saving throw, taking  (3d12) cold damage on a failed save and become petrified until the end of their next turn, or half as much damage on a successful one and they avoid becoming petrified.

Flashfreeze Breath. The dragon exhales paralyzing gas in a 60-foot cone. Each creature in that area must succeed on a DC 12 Constitution saving throw or be paralyzed for 1 minute. A creature takes 2D6 Cold damage at the end of their turns, at which point they can make a DC 15 constitution saving throw to end the effect.