Madness Slug

Madness Slug CR 13

An enormous writhing mass of tentacles and teeth bursts from the ground! Whipping limbs surround its wide, tooth-filled maw, and its entire body is marked randomly with eyes—every time you look at the them they appear to be in a new place. Reality swirls in waves around the monster as the world tries to push it back to whatever nightmare spawned it.

XP 25,600
CE Gargantuan outsider (chaotic, evil, extraplanar)
Init +2; Senses darkvision 60 ft., tremorsense 60 ft.; Perception +23


AC 29, touch 4, flat-footed 29 (–2 Dex, +25 natural, –4 size)
hp 184 (16d10+96) regeneration 5
Fort +16, Ref +9, Will +16; DR 15/magic; Immune acid, cold, mind-affecting effects, paralysis, sleep; SR 21
Defensive Abilities acidic blood


Speed 20 ft., burrow 40 ft., swim 20 ft.
Melee bite +22 (4d8+10), 4 tentacles +20 (2d6+5 plus grab)
Space 20 ft.; Reach 15 ft.
Special Attacks breath weapon (60 ft. cone, Will DC 22, 1d6 wisdom drain), swallow whole (4d8+10 bludgeoning damage, AC 22, hp 18), feeding tentacles


Before Combat Madness slugs burrow or swim while attempting to hide.

During Combat Madness slugs use their breath weapon as often as possible, ideally while attacking an opponent or two with swallow whole.

Morale Madness slugs fight until destroyed.


Str 30, Dex 6, Con 22, Int 12, Wis 18, Cha 9
Base Atk +16; CMB +30 (+34 grapple); CMD 38 (cannot be tripped)
Feats Blind Fight, Bloody Assault, Great Fortitude, Improved Initiative, Improved Natural Armor, Iron Will, Multiattack, Power Attack
Skills Knowledge (arcana) +20, Knowledge (planes) +20, Perception +23, Sense Motive +23, Spellcraft +20, Stealth +17, Swim +31
Languages telepathy 120 ft.
SQ alternate form (drow witch)


Acidic Blood (Ex)

Madness slug blood can corrode metal on contact. If a creature damages a madness slug with a piercing or slashing weapon made of metal, madness slug blood deals 5d6 points of acid damage to the metal weapon (unlike most forms of energy damage, this damage is not halved when applied to a metal object, although it does still have to penetrate the metal’s hardness).

The weapon’s wielder can halve the damage the weapon takes by making a successful DC 24 Reflex save.

Creatures made of metal that deal slashing or piercing damage to a madness slug with a natural attack take 5d6 points of acid damage (a DC 24 Reflex save halves this damage).

The corrosive elements of the blood fade 1 round after it leaves a madness slugs’s body or it dies. The save DC is Constitution-based.

Alternate Form (Su)

Madness slugs can assume the form (in both body and mind) of any creatures it has completely driven insane, taking the bonuses and abilities it likes best. Madness slugs prefer that of a drow witch (enabling it to cast spells and use hexes). Changing forms is a full-round action that provokes attacks of opportunity.

Aura of Madness (Su)

Any creature within 15 ft. of a madness slug must take a DC 22 Will save or fall under the effects of a confusion spell (CL 16th) for 1d8 rounds.

Whether or not the save is successful, that creature cannot be affected again by a madness slug’s aura of madness for 24 hours. This is a mind-affecting effect.

Breath Weapon (Su)

Madness slugs can spew forth a swirling mass of solidified madness in a 60 ft. cone, dealing 1d6 Wisdom drain to creatures hit by it (DC 24 Will save negates). Madness slugs can use their breath weapon once every 1d4 rounds. An opponent reduced to zero or below in Wisdom by a madness slug’s breath weapon gains a severe insanity from the list below (curable DC 24).

Roll Effect
1–3 Paranoia
4–6 Schizophrenia
7–9 Psychosis
10–12 Multiple personality disorder

See “Sanity and Madness” rules for the specific rules of each one of these types of insanity.

Feeding Tentacles (Ex)

Madness slugs can transfer one creature with the grappled condition from a tentacle to its mouth as a free action at the beginning of its turn. The creature does not lose the grappled condition during the transfer and starts in a madness slug’s mouth with the grappled condition to be either swallowed whole or bitten.

Ferocity (Ex)

A madness slug continues to fight even when reduced to negative hit points.

Horrific Death (Ex)

When a madness slug is first reduced to negative hit points, creatures within its reach take 1d6+16 acid damage. While at negative hit points, a madness slug adds a bonus to all damage equal to its hit dice (+16). When it finally dies, the madness slug dissolves into a pool of unidentifiable goo and reforms on the Plane of Madness after 101 years.

Madness Without, Madness Within (Ex)

A madness slug is madness given form and as such its insides consists of swirling fragmented visions of a variety of insanities. Any creature that has been swallowed whole must make a DC 22 Will save before attempting to cut their way out of a madness slug. Failure results in the creature using its turn trying to maintain their precious grasp on reality; a new save may be attempted next round.

Success means the creature can attempt to cut its way out and it is immune to madness without, madness within for 24 hours. This is a mind-affecting effect.

Voidborn (Ex)

Madness slugs can exist safely in the void of space or similar hostile conditions.


Environment underground
Organization solitary
Treasure quadruple

The demiplane of madness is a maelstrom of insanities. The ground is a deluge of mud made of damaged psychoses that have lost their potency—now they lie dormant and make up the ground of the plane. From this mire structures rise, but not in any conventional sense: floating towers, inverted houses, and impossible buildings that are there one moment and gone the next are common. The inhabitants of this place are no less weird than the dimension itself—hordes of madmen roam the ever-changing landscape and nightmarish creatures prowl the skies.

Section 15: Copyright Notice

Aventyr Bestiary © 2017 AAW GAMES LLC Authors Mike Myler, Jonathan G. Nelson Developers, Michael Allen, Curtis Baum, Wolfgang Baur, Brian Berg, Adam Daigle, Jeffrey Gomez, Joshua Gullion, Jacob Kellogg, Jared Jeanquart, Juan Lucha, Justin Andrew Mason, Jonathan McAnulty, Michael McCarthy, Raven Mimura, Brian Wiborg Monster, Will Myers, Mike Myler, Jason Nelson, Jonathan G. Nelson, Owen K.C. Stephens, Colin Stricklin, Cory Vickruck, Stephen Yeardley Jonathan G. Nelson

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