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A bestiary of parasites, compatible with 5.5e and 5e

Sixty-seven creatures whose lives run through other bodies — living, dead, or built — with the rules for what they leave behind in the people, the ground, and the buildings that survive them, and the order of physicians that has been writing all of it down for longer than anyone can remember.

Every stat block is compatible with 5.5e and 5e. It is tuned mainly for the power level of 5.5e, so some creatures may feel stronger than their listed challenge rating in a 5e game.

The creatures are arranged in three broods. The broods are not related to one another and do not want the same things:

  • Inquiline (chapter 4) infects one person at a time. It is what a party carries away.
  • Sporophore (chapter 5) infects ground rather than people. It is what a party walks into.
  • Necrophore (chapter 6) wants nothing from the living. It is what a party leaves behind, in its dead.

Chapter 3 is the people. It covers the cult that welcomes all three broods, the alchemy an officer of the order carries against them, and twenty-three spells written by three groups who each keep them to themselves.

Read chapters 1 and 2 first. Several of these creatures do most of their work after the fight ends, and their stat blocks depend on the rules around them — the Lazaret’s classifications, the counters each brood runs on, and what magic does and does not do here.

Use as much of it as you want. One creature is an encounter. One line is an adventure. A brood followed to its apex is a campaign arc.

License

Creatures, spells, items, and mechanics. The stat blocks, the spells, the items, and the game mechanics — every field of a creature or spell entry other than a creature's description — are licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0). You are free to share and adapt this material, including commercially, provided you give appropriate credit to Nicola Mustone (openfray.app), provide a link to the license, and indicate if changes were made.

Lore, art, and prose. All descriptive and narrative text — including each creature's description and the chapter text of this work — together with any artwork, is © 2026 Nicola Mustone, all rights reserved. It is published here to be read, and is not licensed for reuse in other products.

Game rules. Conditions, spell names, and rules terminology come from the System Reference Document 5.2.1, used under CC BY 4.0.

This work includes material from the System Reference Document 5.2.1 (“SRD 5.2.1”) by Wizards of the Coast LLC, available at dndbeyond.com/srd. The SRD 5.2.1 is licensed under the Creative Commons Attribution 4.0 International License, available at creativecommons.org/licenses/by/4.0/legalcode.