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Ancient Mithral Dragon

Gargantuan · Dragon · CR 18 · Neutral

Source. Tome of Beasts

20 (natural armor)

297 (17d20+119)

Ability Scores

Core attributes and their modifiers.

STR

DEX

CON

INT

WIS

CHA

Overview

Category Monsters

Size Gargantuan

Type Dragon

Alignment Neutral

XP 20000

Initiative Bonus +3

Movement

Walk 40 ft (12.2 m)

Fly 80 ft (24.4 m)

Swim 20 ft (6.1 m)

Climb 20 ft (6.1 m)

Crawl 20 ft (6.1 m)

Senses

Darkvision 120 ft (36.6 m)

Blindsight 60 ft (18.3 m)

Passive Perception 23

Saving Throws

Dexterity +9 Constitution +13 Intelligence +13 Wisdom +13 Charisma +13

Skills

Athletics +15 History +13 Insight +13 Intimidation +13 Perception +13 Persuasion +13

Languages

Celestial, Common, Draconic, Primordial

Resistances & Immunities

Damage Immunities

acid, thunder

Damage Resistances

bludgeoning, piercing, and slashing from

Condition Immunities

charmed

Environments

Mountain

Traits

Innate Spellcasting

the dragon's innate spellcasting ability is Intelligence (spell save DC 21). It can innately cast the following spells, requiring no material components:

at will: tongues

5/day each: counterspell, dispel magic, enhance ability

Legendary Resistance (3/Day)

If the dragon fails a saving throw, it can choose to succeed instead.

Mithral Shards

Ancient mithral dragons can choose to retain the mithral shards of their breath weapon as a hazardous zone of spikes. Treat as a spike growth zone that does 2d8 magical slashing damage for every 5 feet travelled.

Spellcasting

the dragon is a 15th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 21, +13 to hit with spell attacks). It requires no material components to cast its spells. The dragon has the following wizard spells prepared:

Cantrips (at will): acid splash, light, mage hand, minor illusion, prestidigitation
1st Level (4 slots): charm person, expeditious retreat, magic missile, unseen servant
2nd Level (3 slots): blur, hold person, see invisibility
3rd Level (3 slots): haste, lightning bolt, protection from energy
4th Level (3 slots): dimension door, stoneskin, wall of fire
5th Level (2 slots): polymorph, teleportation circle
6th Level (1 slot): guards and wards
7th Level (1 slot): forcecage
8th Level (1 slot): antimagic field

Actions

Bite

+15 to hit, reach 15 ft (4.6 m). Hit: 2d12 piercing damage.

Melee Weapon Attack: +15 to hit, reach 15 ft., one target. Hit: 22 (2d12 + 9) piercing damage.

Breath Weapon

Recharge 5–6

A mithral dragon can spit a 60-foot-long, 5-foot-wide line of metallic shards. Targets in its path take 59 (17d6) magical slashing damage and lose another 10 hit points from bleeding at the start of their turns for 6 rounds; slashing and bleed damage is halved by a successful DC 21 Dexterity saving throw. Only magical healing stops the bleeding before 6 rounds. The shards dissolve into wisps of smoke 1 round after the breath weapon's use.

Claw

+15 to hit, reach 10 ft (3 m). Hit: 2d8 slashing damage.

Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 18 (2d8 + 9) slashing damage, and the target loses 5 hit point from bleeding at the start of each of its turns for six rounds unless it receives magical healing. Bleeding damage is cumulative; the target loses 5 hp per round for each bleeding wound it's taken from a mithral dragon's claws.

Frightful Presence

Each creature of the dragon's choice that is within 120 feet of the 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 its turn, 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.

Multiattack

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

Tail

+15 to hit, reach 20 ft (6.1 m). Hit: 2d10 bludgeoning damage.

Melee Weapon Attack: +15 to hit, reach 20 ft., one target. Hit: 20 (2d10 + 9) bludgeoning damage.

Wing Attack (Costs 2 Actions)

The dragon beats its wings. Each creature within 10 feet of the dragon must succeed on a DC 23 Dexterity saving throw or take 18 (2d8 + 9) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.

Legendary Actions

Detect

Cost 1

The dragon makes a Wisdom (Perception) check.

Tail Attack

Cost 1

The dragon makes a tail attack.

Wing Attack

Cost 2

About Ancient Mithral Dragon

Ancient Mithral Dragon is a gargantuan dragon with a Challenge Rating of 18. It has a neutral alignment.

In combat, this creature maintains an Armor Class of 20 and possesses 297 hit points (derived from 17d20+119).

Ancient Mithral Dragon has communication capabilities including Celestial, Common, Draconic, Primordial. This allows it to interact verbally with various creatures and characters.

GM Tips: Using Ancient Mithral Dragon

1 tips available

When using Ancient Mithral Dragon in your D&D 5e campaign, consider these tactical approaches:

Flight Control Strategy: Target flying creatures with spells like 'Hold Person', 'Web', or 'Grease' to ground them. Without flight restriction, they can escape melee range easily. Consider area denial spells below their flight altitude to force them into disadvantageous positions.

Player Guide: Facing Ancient Mithral Dragon

1 strategies available

When your party encounters this creature, keep these strategies in mind:

Counter Flight Advantage: This creature can fly! Use ranged attacks, reach weapons, or spells like 'Thunderwave' to push it away. Consider 'Gust of Wind' or 'Earthbind' to ground it. Melee characters need fly speed or flight magic to engage.

Encounter Building Calculator

Standard Party Encounter (4-5 characters):

This creature is a medium encounter for a party of 4 characters of level 18.

High-Level Solo Encounter:

This creature is too powerful for a single level-20 character. You need 2.0 character(s) at maximum level (20) to face this creature.

Experience Point Thresholds:

Medium: 34,200 XP
Hard: 51,300 XP
Deadly: 68,400 XP

Based on D&D 5e Dungeon Master's Guide encounter building guidelines. CR roughly equals party level for medium encounters.

Frequently Asked Questions

What is the challenge rating of Ancient Mithral Dragon?: Ancient Mithral Dragon has a Challenge Rating of 18, making it appropriate for parties of level 18.0.
What type of creature is Ancient Mithral Dragon?: Ancient Mithral Dragon is a Gargantuan Dragon, which affects how certain spells and abilities interact with it.
What languages does Ancient Mithral Dragon speak?: Ancient Mithral Dragon can communicate in Celestial, Common, Draconic, Primordial.