1. Races

Adult Amethyst Dragon

Huge Dragon (Gem), typically Neutral
AC 19 (natural armor)
Initiative +2 (12)
HP 229 (17d12 + 119)
Speed 40 ft., Fly 80 ft. (hover), Swim 40 ft.
mod
save
mod
save
mod
save
Str
25
+7
+7
Dex
14
+2
+7
Con
25
+7
+12
Int
20
+5
+5
Wis
17
+3
+8
Cha
21
+5
+10
Skills Arcana +15Perception +13Persuasion +10Stealth +7
Resistances Force, Psychic
Immunities FrightenedProne
Senses Blindsight 60 ft., Darkvision 120 ft., Passive Perception 23
Languages Common, Draconic, telepathy 120 ft.
CR 16 (XP 15,000, or 18,000 in lair; PB +5) 

Traits

Amphibious. The dragon can breathe both air and water.

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

Actions

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

Bite. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 18 (2d10 + 7) piercing damage plus 9 (2d8) force damage.

Claw. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 11 (1d8 + 7) slashing damage.

Singularity Breath (Recharge 5–6). The dragon creates a shining bead of gravitational force in its mouth, then releases the energy in a 90-foot cone. Each creature in that area must make a DC 20 Strength saving throw. On a failed save, the creature takes 45 (10d8) force damage, and its speed becomes 0 until the start of the dragon's next turn. On a successful save, the creature takes half as much damage, and its speed isn't reduced.

Spellcasting (Psionics). The dragon casts one of the following spells, requiring no spell components and using Intelligence as the spellcasting ability (spell save DC 18):

Bonus Actions

Change Shape. The dragon magically transforms into any creature that is Medium or Small, while retaining its game statistics (other than its size). This transformation ends if the dragon is reduced to 0 hit points or uses a bonus action to end it.

Psychic Step. The dragon magically teleports to an unoccupied space it can see within 60 feet of it.

Legendary Actions

Legendary Action Uses: 3. Immediately after another creature's turn, The dragon can expend a use to take one of the following actions. The dragon regains all expended uses at the start of each of its turns.

  • Claw. The dragon makes one claw attack.

  • Psionics (Costs 2 Actions). The dragon uses Psychic Step or Spellcasting.

  • Explosive Crystal (Costs 3 Actions). The dragon spits an amethyst that that explodes at a point it can see within 60 feet of it. Each creature within a 20-foot-radius sphere centered on that point must succeed on a DC 20 Dexterity saving throw or take 13 (3d8) force damage and be knocked prone.

Lair Actions

On initiative count 20 (losing initiative ties), the dragon can take one of the following lair actions; the dragon can't take the same lair action two rounds in a row:

  • Beguiling Whisper. The dragon telepathically whispers to one creature within range of the dragon's telepathy. The creature must succeed on a DC 15 Wisdom saving throw or be charmed by the dragon until initiative count 20 on the next round. A creature charmed in this way obeys to the best of its ability any command the dragon issues that isn't directly harmful to the creature.

  • Imprisoning Force. The dragon casts the forcecage spell, using its spell save DC and requiring no spell components. The spell ends early if the dragon uses this lair action again or dies.

  • Spatial Projection. The dragon chooses a space it can fit into within the lair. It exists in its own space and the chosen space simultaneously until initiative count 20 on the next round. Whenever it moves or takes an action, it chooses which version of itself is moving or acting. If an effect or attack can target both of the dragon's spaces at the same time, the dragon is affected only once.

Regional Effects

The region surrounding a legendary amethyst dragon's lair is altered by the dragon's magic, creating one or more of the following effects:

  • Background Check. Once per day, the dragon can cast the legend lore spell, requiring no spell components, naming any person, place, or object within 1 mile of the lair as the spell's subject.

  • Crystal Profusion. Amethyst crystals and geodes form along muddy shores and lake beds within 6 miles of the lair.

  • Thriving Wildlife. Fish and other aquatic Beasts reproduce rapidly and thrive in bodies of water within 6 miles of the lair. Foraging in these waters yields twice the usual amount of food.

  • Watery Sight. Water within 6 miles of the lair is a conduit for the dragon's psionic presence. As an action, the dragon can cast the clairvoyance spell, requiring no spell components and targeting any body of water in that region.

If the dragon dies, the populations of aquatic life near the lair return to normal levels over the course of 1d10 days. The existing abundance of amethysts remains, but new crystals and geodes form at a normal rate.

Customizing DragonsFTD p33[–]

You can customize any dragon's stat block to reflect the dragon's unique character. Minor changes such as those below are easy to make and have no impact on a dragon's challenge rating.

Languages. Most dragons prefer to speak Draconic but learn Common for dealing with allies and minions. But given their high Intelligence and long life span, dragons can easily learn additional languages. You can add languages to a dragon's stat block.

Skills. Most dragons are proficient in the Perception and Stealth skills, and many dragons have additional skill proficiencies. As with languages, you can customize a dragon's skill list (even doubling their proficiency bonus with certain skills) to reflect particular interests and activities. You can also give a dragon tool proficiencies, particularly if the dragon spends time in Humanoid form.

Other Traits and Actions. You can borrow traits and actions from other monsters to add unique flavor to a dragon. Consider these examples:

  • Change Shape. You can decide that a dragon acquires this action at a younger age than usual, particularly if you want to feature a dragon in Humanoid form in your campaign:The dragon magically polymorphs into a humanoid or beast that has a challenge rating no higher than its own, or back into its true form. It reverts to its true form if it dies. Any equipment it is wearing or carrying is absorbed or borne by the new form (the dragon's choice).In a new form, the dragon retains its alignment, hit points, Hit Dice, ability to speak, proficiencies, Legendary Resistance, lair actions, and Intelligence, Wisdom, and Charisma scores, as well as this action. Its statistics and capabilities are otherwise replaced by those of the new form, except any class features or legendary actions of that form.

  • Flyby. The dragon is an agile flier, quick to fly out of enemies' reach.The dragon doesn't provoke an opportunity attack when it flies out of an enemy's reach.

  • Mimicry. Impersonating characters or their allies could be a fun trick for a crafty dragon.The dragon can mimic any sounds it has heard, including voices. A creature that hears the sounds can tell they are imitations with a successful DC 13 Wisdom (Insight) check.

  • Rejuvenation. You might decide that dragons in your campaign, being an essential part of the Material Plane, are nearly impossible to destroy. A dragon's life essence might be preserved in the egg from which it first emerged, in its hoard, or in a cavernous hall at the center of the world, just as a lich's essence is hidden in a phylactery.If it has an essence-preserving object, a destroyed dragon gains a new body in 1d10 days, regaining all its hit points and becoming active again. The new body appears within 5 feet of the object.

  • Special Senses. Most dragons have blindsight and darkvision. You might upgrade blindsight to truesight, or you could give a dragon with a burrowing speed tremorsense.

Source: FTD, page 161.