Aereus V2.0

Immutable Form. Aereus V2.0 is immune to any spell or effect that would alter its form.

Mechanical Nature. Aereus V2.0 doesn't need to eat, sleep, or breathe.

Legendary Resistance. (3/Day). If Aereus V2.0 fails a saving throw, it can choose to succeed instead.

Magic Resistance. Aereus V2.0 has advantage on saving throws against spells and other magical effects.

Siege Monster. Aereus V2.0 deals double damage to objects and structures.

Multiattack. Aereus V2.0 can use its Oil Spray. It then makes three attacks: one with its bite and two with its fists.

Bite. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage plus 3 (1d6) fire damage.

Claw. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 13 (2d6 + 6) slashing damage.

Breath Weapon (Recharge 5-6). Aereus V2.0 uses one of the following Breath Weapons:

Fire Tar Breath. Aereus V2.0 sprays flaming tar in a 30 foot-cone. Each creature in that area must make a DC 16 Dexterity saving throw, taking 35 (10d6) fire damage on a failed save or half as much on a successful one. On failed save, a creature is restrained (Escape Strength DC 16). While restrained in this way, a creature takes 10 (3d6) fire damage at the start of each of its turns.

Knock Out Gas. Aereus V2.0 exhales knockout gas in a 60-foot cone. Each creature in that area must succeed on a DC 16 Constitution saving throw or fall unconscious for 10 minutes. This effect ends for a creature if the creature takes damage or someone uses an action to wake it.

Oil Spray. Aereus V2.0 sprays oil in a 30-foot-cone, the area becomes slickened. Each creature in the area must succeed on a DC 16 Dexterity saving throw or become vulnerable to fire damage until the end of the dragon’s next turn. If a creature moves in an oil-slicked area more than 5 feet, it must make a DC 15 Dexterity saving throw, falling prone on a failure.

Tail Sweep. Aereus V2.0 swings its bladed tail. Each creature within 10 feet of the dragon must make a DC 17 Dexterity saving throw, taking 15 (2d8 + 6) slashing damage plus (1d6) cold damage, and is knocked prone on a failed save, or half as much damage and is not knocked prone on a successful one.

Aereus V2.0 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. Aereus V2.0 regains spent legendary actions at the start of its turn.

Tail Sweep. Aereus V2.0 makes a tail sweep attack.

Wing Attack (Costs 2 Actions). Aereus V2.0 beats its wings. Each creature within 15 feet of Aereus V2.0 must succeed on a DC 18 Dexterity saving throw or take 16 (2d6 + 6) bludgeoning damage and be knocked prone. Aereus V2.0 can then fly up to half its flying speed.

Frost Armor (Cost's 2 Actions). Aereus V2.0 gains 20 Temporary Hit Points, If a creature hits you with a melee attack while you have these hit points, the creature takes 20 cold damage.