Dissimortuum

Dissimortuum have three arms and an imposing mask bound to its face by strips of rotting flesh. They stalk the edges of small settlements and the corners of larger ones, picking off vulnerable targets and stripping body parts from its victims, collecting them into a large sack it drags behind it. They will also scavenge from battlefields and graveyards that are not protected from the presence of the undead, until they have the material needed to craft a new mask and body for a new dissimortuum. It will take usually at minimum a month for a dissimortuum to craft a new mask, and may take much longer if it cannot find a good source of satisfactory bones, but they are functionally immortal, and so are unendingly patient. Once finished, a dissimortuum mask is nearly indestructible, and even if the creature is destroyed the mask will survive. It may be a tempting souvenir for the killer, or it may be left behind and picked up by a passer-by, but anyone who puts the mask on risks being taken over by the dissimortuum’s remaining will, blanking out for hours each day while it gathers body parts and builds a new body for the destroyed undead. In this way, even a destroyed dissimortuum may return, the mask affixed to its face once again giving it new unlife to continue its quest to create more of itself.

Inspired by the Tome of Beasts 1. This post came out a week ago on my Patreon. If you want to get access to all my monster conversions early, as well as access to my premade adventures and other material I’m working on, consider backing me there!

Pathfinder 2e

Dissimortuum Creature 7
Rare, Medium, Undead, Unholy
Perception +13; darkvision
Languages Common
Skills Athletics +14, Stealth +13
Str +2, Dex +0, Con +3, Int -1, Wis +0, Cha +4
AC 23; Fort +18, Ref +11, Will +13
HP 115 (void healing); Immunities bleed, death effects, disease, poison, unconscious; Resistances physical 10 (except silver); Weaknesses 10 silver
Frightful Presence (aura, emotion, fear, mental) 60 feet, DC 25
Speed 25 feet, 25 climb
Melee claw +15 (agile), Damage 2d6+6 slashing
Rapid Claws [2 actions] The dissimortuum makes three claw Strikes, each against a different target. These attacks count toward the dissimortuum’s multiple attack penalty, but the multiple attack penalty doesn’t increase until it makes all the attacks.
Sneak Attack The dissimortuum deals an extra 1d6 precision damage to off-guard or frightened creatures.

Dissimoruum’s Mask Item 7
Rare, Cursed, Magical
Usage worn mask; Bulk L
This indestructible bone mask doesn’t detect as magical. If worn it afflicts you with dissimortuum’s curse.
Dissimortuum’s Curse (curse, incapacitation, void) Saving Throw DC 23 Will; Effect You take 2d6 void damage, and the mask fuses with you. You become controlled by the mask. While controlled, for 1d4 hours each day you will gather the necessary components to build a new body for the dissimortuum that originally owned the mask. You don’t remember this time. It takes 24 combined hours of uninterrupted work to create the dissimortuum, placing the mask on it to animate it and ending the curse.

13th Age

Dissimortuum
Double-Strength 4th level troop [undead]
Initiative: +7
Claws +9 vs. AC (3 attacks) – 9 damage.
Crush Fearful: The dissimortuum deals +1 damage against frightened targets.
Fear: Enemies engaged with the dissimortuum who are below 18 hit points are dazed and do not add the escalation die to their attack.
Wall Climber.
Resist Negative Energy 18+.
AC 19 PD 17 MD 16 HP 102