Gargantuan dragon (gem), Lawful Neutral
| Armor Class | 20 (natural armor) |
|---|---|
| Hit Points | 332 (19d20 + 133) |
| Speed | 40 ft., burrow 30 ft., fly 80 ft. |
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 25 (+7) | 12 (+1) | 25 (+7) | 20 (+5) | 18 (+4) | 20 (+5) |
| Saving Throws | Cha +12, Con +14, Dex +8, Wis +11 |
|---|---|
| Skills | Arcana +12, Deception +12, Perception +18, Stealth +8 |
| Damage Vulnerabilities | — |
| Damage Resistances | fire; psychic |
| Damage Immunities | — |
| Condition Immunities | — |
| Senses | blindsight 60 ft., darkvision 120 ft., passive Perception 28 |
| Languages | Common, Draconic, telepathy 120 ft. |
| Challenge | 21 |
If the dragon fails a saving throw, it can choose to succeed instead.
The dragon can burrow through solid rock at half its burrowing speed and can leave a 20-foot-diameter tunnel in its wake.
The dragon can cast mirage arcane, requiring no spell components and using Intelligence as the spellcasting ability.
The dragon makes one Bite attack and two Claw attacks.
Melee Attack Roll: +14 to hit, reach 15 ft., one target. Hit: 18 (2d10 + 7) piercing damage plus 10 (3d6) psychic damage.
Melee Attack Roll: +14 to hit, reach 10 ft., one target. Hit: 14 (2d6 + 7) slashing damage.
The dragon exhales a wave of psychic dissonance in a 90-foot cone. Each creature in that area must make a DC 22 Intelligence saving throw. On a failed save, the creature takes 56 (16d6) psychic damage, and until the end of its next turn, when the creature makes an attack roll or an ability check, it must roll a d8 and reduce the total by the number rolled. On a successful save, the creature takes half as much damage with no additional effects.
The dragon makes one Claw attack.
The dragon uses Psychic Step or Spellcasting.
The dragon creates a dancing mote of green flame around a creature it can see within 60 feet of it. The target must succeed on a DC 20 Dexterity saving throw or take 42 (12d6) fire damage.
The dragon casts one of the following spells, requiring no spell components and using Intelligence as the spellcasting ability (spell save DC 20):
At will: mage hand (the hand is invisible), minor illusion
1 each/day: detect thoughts, dispel magic, etherealness, major image, mislead