Multiattack. The dragon makes one Bite attack and two Claw attacks.

Bite. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 15 (2d10 + 4) piercing damage. Instead of dealing damage, the dragon can end one magical effect of its choice of 3rd level or lower on the target.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage, and if the target isn't a Construct or Undead, it must succeed on a DC 14 Constitution saving throw or lose 3 (1d6) hp at the start of each of its turns as a piece of metallic claw breaks off in the wound. Any creature can take an action to remove the claw with a successful DC 12 Wisdom (Medicine) check. The claw pops out of the wound if the target receives magical healing.

Shard Breath (Recharge 5-6). The mithral dragon spits metallic shards in a 30-foot cone. Each creature in that area must make a DC 14 Dexterity saving throw, taking 28 (8d6) slashing damage on a failed save, or half as much damage on a successful one. The area becomes difficult terrain for 1 minute, then the shards dissolve into wisps of silvery smoke.