Astral Dreadnought 5e: Stats and Guide for Players & DMs

Last Updated on November 7, 2023

Astral Dreadnought

Gargantuan Monstrosity (Titan), unaligned

  • Size:  Gargantuan
  • Creature Type: Monstrosity (Titan)
  • Alignment: Unaligned
  • AC: 20 (natural armor)
  • Hit Points: 297 (17d20 + 119)
  • Speed: 15 ft., fly 80 ft. (hover)
  • STR: 28(+9), DEX: 7(-2), CON: 25(+7), INT: 5(-3), WIS: 14(+2), CHA: 18(+4)
  • Saving Throws: Dex +5, Wis +9
  • Skills: Perception +9
  • Damage Resistances: Bludgeoning, piercing, and slashing from nonmagical attacks
  • Condition Immunities: Charmed, exhaustion, frightened, paralyzed, petrified, poisoned, prone, stunned
  • Senses: Darkvision 120 ft., Passive Perception 19
  • Languages
  • Challenge Rating: 21 (33,000 XP)       
  • Proficiency Bonus: +7

Antimagic Cone. The dreadnought’s eye creates an area of antimagic, as in the antimagic field spell, in a 150-foot cone. At the start of each of its turns, it decides which way the cone faces. The cone doesn’t function while the eye is closed or while the dreadnought is blinded.

Astral Entity. The dreadnought can’t leave the Astral Plane, nor can it be banished or otherwise transported out of that plane.

Demiplanar Donjon. Anything the dreadnought swallows is transported to a demiplane that can be entered by no other means except a wish spell or the dreadnought’s Bite and Donjon Visit. A creature can leave the demiplane only by using magic that enables planar travel, such as the plane shift spell. The demiplane resembles a stone cave roughly 1,000 feet in diameter with a ceiling 100 feet high. 

Like a stomach, it contains the remains of past meals. The dreadnought can’t be harmed from within the demiplane. If the dreadnought dies, the demiplane disappears, and everything inside it appears around the dreadnought’s corpse. The demiplane is otherwise indestructible.

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

Sever Silver Cord. If the dreadnought scores a critical hit against a creature traveling by means of the astral projection spell, the dreadnought can cut the target’s silver cord instead of dealing damage. 

Unusual Nature. The dreadnought doesn’t require air, food, drink, or sleep.


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

Bite. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 36 (5d10 + 9) force damage. If the target is a Huge or smaller creature and this damage reduces it to 0 hit points or it is incapacitated, the dreadnough swallows it. The swallowed target, along with everything it is wearing and carrying, appears in an unoccupied space on the floor of the Demiplanar Donjon.

Claw. Melee Weapon Attack: +16 to hit, reach 20 ft., one target. Hit: 19 (3d6 + 9) force damage.

Legendary Actions

The dreadnought can take three legendary actions, choosing from the options below. Only one legendary option can be used at a time and only at the end of another creature’s turn. The dreadnought regains spent legendary actions at the start of its turn.

  • Multiattack. The dreadnought makes one Bite attack and two Claw attacks.
  • Claw. The dreadnought makes one Claw attack.
  • Donjon Visit (Costs 2 actions). One huge or smaller creature that the dreadnought can see within 60 feet of it must succeed on a DC 19 Charisma saving throw or be teleported to an unoccupied space on the floor of the Demiplanar Donjon. At the end of the target’s next turn, it reappears in the space it left or in the nearest unoccupied space if that space is occupied.
  • Psychic Projection (Costs 3 actions). Each creature within 60 feet of the dreadnought must make a DC 19 Wisdom saving throw, taking 26 (4d10 + 4) psychic damage on a failed save or half as much damage on a successful one. 

Guide to the Astral Dreadnought

Not every creature you come across in a game of D&D is going to be derived from classical fantasy. 

Sure, from demons to pegasus and goblins to dryads, there is a lot we pull from mythology and world culture, but that doesn’t mean we don’t see some insane creatures pulled straight from nightmares.

Today, we’re going to be talking about one such creature, the Astral Dreadnought. This terrifying monstrosity is like a boogeyman that haunts the void, a deadly threat to any wishing to travel the planes. 

In this article, we’ll be going over the monster’s sizable statblock and talking about the ins and outs of the creature in general. How to run it, when to use it, its history, and more; all of that information curated just for you. Read on below!

What Is an Astral Dreadnought?

Well, ironically, it’s not a giant ship that allows you to travel the astral plane as those of you familiar with naval history might be thinking. No, an Astral Dreadnought is one of the most terrifying things you could come across while traveling the astral plane, great monstrosities seeking to devour anything they encounter.

I think the first place to start is the absolutely earth-shattering size of these creatures. 

These gargantuan titans are some 20-35 feet tall with great serpentine bodies ending in a head not unlike that of a grotesquely deformed beholder. 

A single eye, shimmering with reflections of the cosmos, sits above a massive toothy maw. From their head-torso extend two muscular appendages with claws that could easily snap an adventurer in two.

They have a singular purpose: to devour anything wandering the astral plane.


So, what spawns such a voracious appetite? Well, according to Mordenkainen, who, apparently, in WotC canon is an unreliable narrator, astral dreadnoughts were formed long ago by Tharizdun, the chained god.

Of course, 5e literature also tells us that these creatures have been around since before the multiverse existed. Tharizdun may have created the Abyss with the help of obyriths, but he certainly didn’t create the multiverse.

I guess that means we have two options, and you can decide what you want to believe. On one hand, astral dreadnoughts are as old as, if not older than, the multiverse itself. Since the dawn of time, they’ve roamed the void searching to sate their endless hunger.

Alternatively, dreadnoughts were created by an angry, disgruntled god terrified of mortals traveling the planes. They were created as, essentially, protectors of great knowledge and power. With them roaming the void that is the Astral Plane, the gods could remain mighty.

Or, you could just make up your own origin for these creatures. After all, this is D&D. All the sourcebooks in the world don’t really matter, they’re just inspiration for you and your friends to interpret and riff off of in an exciting storytelling experience.

Astral Dreadnoughts in Combat

A remorseless, indiscriminate hunter, an astral dreadnought employs terrifying, if unimaginative, tactics.” 

– Mordenkainen’s Tome of Foes

It’s no wonder this line didn’t survive the rewrite from Tome of Foes to Monsters of the multiverse. Clearly, even the editors at WotC are aware of just how uninspired this “legendary” creature really is. 

There are, fortunately, a few things that make this a bit of an interesting fight.

First, the dreadnought has resistance (takes half damage) from bludgeoning, piercing, and slashing damage from nonmagical attacks. This is pretty standard for big bads, but there’s more. 

Antimagic Field

The dreadnought also creates a pretty substantial antimagic field.

A 150-foot cone of antimagic originates from the eye of the dreadnought, and at the beginning of each of its turns, it decides which way the cone is facing. 

That is a very substantial ability since it will render not only spells but magical weapons as well completely inert.

Essentially, if you’re within the area of the cone, you’re almost guaranteed to be dealing resisted damage. There are really few exceptions. 

So okay, this thing tries to keep the biggest threats within its antimagic field, rendering them almost useless. Then what?

Claw and Bite Attacks

That’s when it becomes not very exciting. It gets a pretty standard claw/claw/bite multiattack, something that the party has probably been dealing with since level 3. 

Alright, maybe that’s too judgemental. In fact, both the claw and the bite have ways to become exciting and interesting attacks.

The Silver Cord

If the dreadnought gets a critical hit on an adventurer who is in the astral plane via the Astral Projection spell, it can sever the silver cord instead of dealing damage. 

If you were unaware, this separates your soul and body, resulting in instant death. So yeah, just hope this thing doesn’t roll a 20.

This is actually very different from the inception of the dreadnought’s ability to sever silver cords. In 3e, it had to be behind a creature and make an attack against the cord specifically. 

The cord had 20 hit points and shared the player’s AC, meaning it was much less of a guaranteed death.

Now, you have a 5% chance of instant death when you fight this thing, and that’s before we take into consideration just how many claw attacks it gets between the multiattack and legendary actions combined.

Legendary Actions

Then, of course, we have legendary actions to use at our heart’s desire: a claw attack, which costs one action; a one-way trip to the stomach, which costs two actions; and a decent AOE blast of psychic damage, which uses up all three legendary actions for a round.

Since WotC tells us this thing is an unimaginative combatant, I imagine it will mostly use the claw attack. This improves its chances of getting an instant kill and gives it the most amount of actions in a round.

If it needs to sedate a creature, it will probably use the Donjon Visit action. This has a small chance of failure, but if it works, the dreadnought doesn’t have to worry about the creature for a round of combat. 

As for Psychic Protection, this really feels like a death throw. Sure, you could use it every turn if a lot of creatures are ganging up on the dreadnought, but it will seek to get more actions rather than AOE. That’s how unintelligent beasts tend to operate, and for all intents and purposes, that’s what we’re dealing with.

Fighting the Astral Dreadnought

The dreadnought is almost as uninteresting from the player’s point of view as it is from the DM’s. 

The main focus should be on eliminating its antimagic field, and after that, you just have to dish out some quick damage before it overtakes you.

Having a caster stay outside of its antimagic field is crucial, even if you don’t have a way to blind it. This way, you can continue to deal uninhibited damage. 

Unfortunately, that means staying close to the monster since you’ll need to be as far away from it as your movement speed (cones are as wide as the distance from their origin).

That’s fine though. The dreadnought has an absolutely insane movement speed, so it’s not like you could outrun it if you tried.

As for blinding it, you’ll have to be creative. 

Some material, the barbarian, or anything big enough to cover the single eye of a gargantuan monstrosity should do the trick.

Beyond that, it’s simple. If you manage to take down the antimagic field, use magic to destroy it. If you don’t, hope it doesn’t get many critical hits, and deal as much damage as you can.

I hope you can enjoy a fun adventure with this creature, although it certainly could use some improvements. Perhaps we’ll take a stab at remodeling it somewhere down the line. For now, happy adventuring.

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