Weredragon

Shapechanger. The weredragon can use its action to polymorph into a dragon-humanoid hybrid or into a dragon (changes size category to large), or back into its true form, which is humanoid. Its statistics, other than its AC, are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Multiattack. In dragon form, the weredragon makes one bite attack and two claw attacks. In humanoid form, it makes two greatsword attacks. In hybrid form, it can attack like a dragon or a humanoid.

Lunar Breath (Dragon Form Only, Recharge 5-6). The weredragon exhales pale silver light in a 60-foot line that is 5 feet wide which engulfs creatures in this area with ghostly flames. Each creature in that line must make a DC 16 Dexterity saving throw, taking 55 (10d10) radiant damage on a failed save, or half as much damage on a successful one. A shapechanger makes its saving throw with disadvantage. If it fails, it also instantly reverts to its original form and can’t assume a different form until it leaves the breath's light.

Bite (Dragon or Hybrid Form Only). Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 29 (2d10 + 6) piercing damage (plus 3 (1d6) radiant damage. When in dragon form only). If the target is a humanoid, it must succeed on a DC 10 Constitution saving throw or be cursed with weredragon lycanthropy.

Claw (Dragon or Hybrid Form Only). Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 9 (2d6 + 6) slashing damage.

Greatsword (Humanoid Form Only). Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 9 (2d6 + 6) slashing damage.