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Dragon, Aionian

Huge dragon, chaotic evil

Armor Class 19 (natural armor)
Hit Points 230 (20d12 + 100)
Speed 40 ft.

22 (+6) 10 (+0) 21 (+5) 16 (+3) 17 (+3) 16 (+3)

Saving Throws Dexterity+6, Constitution+11, Wisdom+9, Charisma+9
Damage Immunities acid, poison
Damage Resistances bludgeoning, piercing, and slashing from nonmagical attacks
Condition Immunities poisoned, prone
Skills Perception +9, Stealth +6
Senses darkvision 120 ft., passive Perception 19
Languages Draconic
Challenge 17 (18,000 XP)

Special Traits

  • Legendary Resistance (3/Day). If the dragon fails a saving throw, it can choose to succeed instead.
  • Acid Blood. A creature within 5 feet of the aionian dragon takes 5 (1d10) acid damage whenever it hits the dragon with a melee attack that deals piercing or slashing damage.
  • Wakeful. The aionian dragon never sleeps.


  • Multiattack. The dragon can use its Frightful Presence. It then makes two attacks: one with its bite and one to constrict.
  • Bite. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage plus 7 (2d6) acid damage.
  • Constrict. Melee Weapon Attack: +12 to hit, reach 15 ft., one Large or smaller creature. Hit: 17 (2d10 + 6) bludgeoning damage. The target is grappled (escape DC 20) if the aionian dragon isn’t already constricting a creature, and the target is restrained until this grapple ends.
  • Acid Breath (Recharge 5-6). The dragon exhales acid in a 60-foot cone. Each creature in that cone must make a DC 14 Dexterity saving throw, taking 54 (12d8) acid damage on a failed save, or half as much damage on a successful one.
  • 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 17 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.
  • Swallow. The aionian dragon makes one bite attack against a Medium or smaller target it is grappling. If the attack hits, the target is also swallowed, and the grapple ends. While swallowed, the target is blinded and restrained, it has total cover against attacks and other effects outside the aionian dragon, and it takes 21 (6d6) acid damage at the start of each of the aionian dragon’s turns. An aionian dragon can have only one creature swallowed at a time. If the aionian dragon takes 30 damage or more on a single turn from the swallowed creature, the aionian dragon must succeed on a DC 19 Constitution saving throw at the end of that turn or regurgitate the creature, which falls prone in a space within 10 feet of the aionian dragon. If the aionian dragon dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 15 feet of movement, exiting prone.
  • Tail. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 15 (2d8 + 6) bludgeoning damage.

Legendary Actions

The aionian 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 aionian 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.
  • Chomp (Costs 2 Actions). The aionian dragon makes one bite attack or uses its Swallow.


This serpent’s crest shines with a golden gleam. Its eyes flash like fire and its whole body is suffused with venom.

Between its triple rows of teeth, its three-forked tongue flickers.

Nature’s Guardian. Aionian dragons are guardians by nature and when not hunting, spend most of their time resting in riverside caves. They are extremely territorial and will attack any perceived intruders.

Section 15: Copyright Notice

5E RPG: Ancient Adventures. Copyright 2020, Mal and Tal, LLC; Author Michael Tresca.