Gargantuan dragon, lawful neutral
Armor Class 20 (natural armor)
Hit Points 498 (30d20 + 200)
Speed 60 ft., burrow 40 ft., fly 100 ft.
Saving Throws Str +11, Dex +17, Con +10, Int +13, Wis +13, Cha +8
Skills Acrobatics +17, Animal Handling +13, Arcana +13, History +13, Insight +13, Medicine +13, Nature +13, Perception +13, Sleight of Hand +17, Stealth +17, Survival +13
Damage Vulnerabilities necrotic
Damage Resistances cold
Damage Immunities radiant
Senses blindsight 60ft., darkvision 120 ft., passive Perception 23
Languages Common, Draconic
Challenge 22 (41,000 XP)
Chameleon Skin. The dragon has advantage on Dexterity (Stealth) checks made to hide.
Legendary Resistance (3/Day). If 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: +15 to hit, reach 15 ft., one target. Hit: 19 (2d10 + 9) necrotic damage.
Claw. Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) slashing damage.
Tail. Melee Weapon Attack: +15 to hit, reach 20 ft., one target. Hit: 17 (2d8 + 8) 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 19 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 successful or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.
Lunar Breath (Recharge 5-6). The dragon exhales a beam of moonlight in a 90-foot line that is 10 feet wide. Each creature in that line must make a DC 22 Dexterity saving throw, taking 67 (15d8) radiant damage and 29 (6d8) cold damage on a failed save, or half as much damage on a successful one.
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 23 Dexterity saving throw or take 15 (2d6 + 8) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.
Lunar Pulse (Costs 3 Actions) The dragon pulses with moonlight. Each creature in a 25 ft radius must make a DC 22 dexterity saving throw. On a successful save it takes half damage, on a failed save it takes 13 (2d10) radiant damage and 9 (2d8) cold damage, and is blinded.
Lunar Dragons have iridescent scales, which seem to change colors as the light flows over it. They make their lair in the middle of plains, and hilly areas. They have a love of gems and will gather them in ridiculous amounts to cover it's lair. It's lair has large crystals protruding from the walls, floor and ceiling, shining light throughout its lair, freezing anything stupid enough to pass through with it's radiance. Something about the dragon seems to shimmer and change as it is struck by the light of dawn.