Ancient Gray Dragon

Amphibious. Th e dragon can breathe air and water.

Ice Walk. The dragon can move across and climb icy surfaces without needing to make an ability check. Additionally, difficult terrain composed of ice or snow doesn't cost it extra moment.

Legendary Resistance (3/day). When the dragon fails a saving throw it can choose to succeed instead.

Multiattack. The dragon can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +16 to hit, reach 15 ft., one target. Hit: 20 (2d10 + 9) piercing damage, 9 (2d8) acid damage plus 9 (2d8) cold damage.

Claw. Melee Weapon Attack: +16 to hit, reach 10ft., on'e target. Hit: 16 (2d6 + 9) slashing damage.

Tail. Melee Weapon Attack: +16 to hit, reach 20 ft., one target. Hit: 18 (2d8 + 9) bludgeoning damage.

Frightful Presence. Each creature of the dragon's choice that is within 120 feet ofthe dragon and aware of it must succeed on a DC 21 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successfu l or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.

Freezer Burn (Recharge 5-6). The dragon exhales frozen acid in a 90-foot cone. Each creature in that area must succeed on a DC 23 Constitution saving throw taking 72 (16d8) cold damage on a failed save or half as much damage on a success. On the dragons next turn any creature in the same area must succeed on a DC 23 Dexterity saving throw taking 67 (15d8) Acid damage on a failed save or half as much damage on a success as the frozen acid warms up and melts back into liquid acid.

The dragon can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn . The dragon regains spent legendary actions at the start of its turn.

Detect. The dragon makes a Wisdom (Perception) check.

Tail Attack. The dragon makes a tail attack.

Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 15 feet of the dragon must succeed on a DC 24 Dexterity saving throw or take 16 (2d6 + 9) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.