Elemental, Mudslide

Gargantuan elemental, chaotic neutral

Armor Class 19 (natural armor)
Hit Points 330 (20d20+120)
Speed 40 ft., burrow 40 ft., climb 40 ft., swim 30 ft.

24 (+7) 20 (+5) 23 (+6) 20 (+5) 25 (+7) 21 (+5)

Saving Throws Dex +12, Int +12, Cha +12
Skills Arcana +12, Nature +12, Perception +14
Damage Resistances fire, lightning, thunder; bludgeoning, piercing, and slashing
Damage Immunities acid, cold, poison
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned, stunned, unconscious
Senses darkvision 240 ft., blindsight 30 ft., tremorsense 60 ft., passive Perception 24
Languages Aquan, Common, Primordial, Terran
Challenge 24 (62,000 XP)


  • Amorphous. In addition, the elemental can move through a space as narrow as 1 foot wide without squeezing.
  • Earth Glide. The elemental can burrow through nonmagical, unworked earth and stone. While doing so, the elemental doesn’t disturb the material it moves through.
  • Elemental Concentration. The elemental does not need to concentrate on conjure elemental spells that it casts.
  • Innate Spellcasting. The elemental’s innate spellcasting ability is Wisdom (spell save DC 22). It can innately cast the following spells, requiring no material components:
  • Legendary Resistance (3/Day). If the elemental fails a saving throw, it can choose to succeed instead.
  • Magic Resistance. The elemental has advantage on saving throws made against spells and other magical effects.
  • Magic Weapons. The elemental’s weapon attacks are magical.
  • Mixed Tongue. The elemental prefers to speak in a hybrid of Aquan and Terran. Creatures that know both languages have advantage on Wisdom (Insight) and Charisma checks made against the elemental.
  • Regeneration. The elemental regains 10 hit points at the start of its turn if it has at least 1 hit point.
  • Siege Monster. The elemental deals double damage to objects and structures.
  • Storm Form. The elemental can move through a space as narrow as 1 inch wide without squeezing. A creature that touches the elemental or hits it with a melee attack while within 10 feet of it takes 16 (3d10) lightning damage. In addition, the elemental can enter a hostile creature’s space and stop there. The first time it enters a creature’s space on a turn, that creature takes 16 (3d10) lightning damage.


  • Multiattack. The elemental attacks three times.
  • Slam. Melee Weapon Attack: +12 to hit, reach 20 ft., one target. Hit: 16 (2d10+5) bludgeoning damage plus 9 (2d8) fire damage and 9 (2d8) lightning damage.
  • Lightning Strike. Ranged Weapon Attack: +15 to hit, range 300/900 ft., one target. Hit: 35 (5d10+8) lightning damage.
  • Whirlwind. Each creature in the elemental’s space must make a DC 22 Strength saving throw. On a failure, a target takes 32 (6d8+5) bludgeoning damage and is flung up to 40 feet away from the elemental in a random direction and knocked prone. If a thrown target strikes an object, such as a wall or floor, the target takes 9 (2d8) bludgeoning damage for every 10 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 22 Dexterity saving throw or take the same damage and be knocked prone.


The elemental 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 elemental regains spent legendary actions at the start of its turn.

  • Steam Cloud. Until the start of its next turn, the elemental is surrounded by a 20-foot-radius sphere of steam that makes the area heavily obscured.
  • Supercharge. The elemental briefly polarizes the static charge all around it to create a magnetic contraction. Creatures within 200 feet that are wielding metal weapons or wearing metal armor make a DC 21 Strength saving throw or are restrained until the end of the round as their ferrous armaments pin them against the ground.
  • Casts a Spell (Costs 2 Actions). The elemental casts a spell.


  • Multiattack. The elemental uses Engulf and attacks once.
  • Slam. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 29 (4d10+7) bludgeoning damage.
  • Mudball. Ranged Weapon Attack: +14 to hit, range 250/750 ft., one target. Hit: 21 (4d6+7) bludgeoning damage and the target is grappled (escape DC 22).
  • Engulf. The elemental moves up to its speed. While doing so, it can enter Huge or smaller creatures’ spaces. Whenever the elemental enters a creature’s space, the creature must make a DC 22 Dexterity saving throw. On a successful save, the creature can choose to be pushed 20 feet back or to the side of the elemental. A creature that chooses not to be pushed suffers the consequences of a failed saving throw. On a failed save, the elemental enters the creature’s space, and the creature takes 27 (6d8) bludgeoning damage and is engulfed. The engulfed creature can’t breathe, is restrained, has total cover, and takes 36 (8d8) bludgeoning damage at the start of each of the elemental’s turns. When the elemental moves, the engulfed creature moves with it. In addition, any creatures the elemental has grappled make a DC 22 Strength saving throw or are also engulfed. An engulfed creature can try to escape by taking an action to make a DC 22 Strength check. On a success, the creature escapes and enters a space of its choice within 5 feet of the elemental.


The elemental 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 elemental regains spent legendary actions at the start of its turn.

  • Attack. The elemental makes an attack.
  • Casts a Spell (Costs 2 Actions). The elemental casts a spell.
  • Mud Flood (Costs 2 Actions). The elemental unleashes a wave of mud in a 50-foot radius. Creatures in the area are knocked prone and make a DC 22 Strength saving throw, taking 27 (6d8) bludgeoning damage on a failed save, or half as much on a successful one. A creature that takes 20 or more bludgeoning damage is grappled (escape DC 22).


In the sludge where the Plane of Earth and Plane of Water meet perhaps the strangest of the epic elementals are formed. These creatures are unlike their kin most of all in how they are created, slowly gestating in ancient eddies that become perpetual whirlpools of grime that ever so slowly distill into intellects. Although mudslides do not experience great violence when they are wrought, their very bodies are in a never ending painful flux between solidity and liquidity so each knows suffering as a constant companion as well as the need for patience. The schemes employed by these primordial entities can sometimes take centuries to come to pass but they are utterly ruthless, bringing ruin to empires with no thought for all the deaths wrought by their doings.

Mudslide elementals are especially dangerous because they’ve been known to permanently place themselves within other dimensions with far greater ease than other epic elementals by using planeshift to gradually transport small sections of their bodies every day over the course of a year, creating massive mudpiles in their destination plane. Once there permanently a mudslide spreads its body far and wide, at first bringing growth and fertility that mortals hail as a miracle (especially when it inadvertently helps put out wildfires). Ultimately the primordial elemental has a far different goal however, destabilizing worlds a region at a time—when its work is done, in a matter of days whole settlements suddenly collapse in on themselves causing mass hysteria as people panic in the destructive mires. Disease, death, and starvation come in the mudslide’s wake, and though it is slow to act, none of its planar kin are as devastating to life.

Sucking Wounds. When a creature scores a critical hit against the elemental with a melee weapon attack, it must succeed on a DC 22 Strength saving throw or its weapon becomes embedded in the elemental. A creature attacking with a natural weapon or unarmed strike gains the grappled condition (escape DC 22), and when the elemental moves the grappled creature moves with it.

Section 15: Copyright Notice

Tome of Beasts 2. © 2020 Open Design LLC; Authors Wolfgang Baur, Celeste Conowitch, Darrin Drader, James Introcaso, Philip Larwood, Jeff Lee, Kelly Pawlik, Brian Suskind, Mike Welham.

This is not the complete section 15 entry - see the full license for this page