weredragon

Shapechanger. The weredragon can use its action to polymorph into a dragon-humanoid hybrid, into a red dragon wyrmling , 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.

Keen gold/treasure sense:if a creature within 100 feet of the weredragon has a magic item that is rare or higher the weredragon is drawn to it and will always attack the enemy with the most gold in a fight.

Legendary Resistance (3/Day). If the weredragon fails a saving throw, it can choose to succeed instead.

Multiattack. (Humanoid or Hybrid Form Only). The weredragon makes two attacks from any of his attacks.

Bite ( Hybrid Form Only). +7 to hit 5 feet ignores resistance to piercing damage 4 (2d6 +3) piercing damage on a successful hit the target must succeed a dc 12 con save

Claws. (Hybrid Form Only). Melee Weapon Attack: +6 to hit 5 feet ignores resistance to slashing damage. 3(2d10 +3) slashing damage

Spear (Humanoid Form Only). Melee or Ranged Weapon Attack: +4 to hit, reach 5 ft. or range 20/60 ft., one creature. Hit: 5 (1d6 + 2) piercing damage, or 6 (1d8 + 2) piercing damage if used with two hands to make a melee attack.

Force tail(hybrid form only) Melee weapon attack +7 to hit 15 feet 4(2d8) force damage

as a reaction if a creature within 15 feet of the weredragon casts a spell or uses a magical quality of a magic weapon the weredragon can  run to the creature (it still provokes opportunity attacks) and attack with either its claws or bite or spear (depends on form and your choice).