Though not technically a disease, the marrow ooze parasite nonetheless infects its victims with its presence. A marrow ooze enters the body through a wound or exposed orifice (potentially the mouth or ears) while the victim is sleeping, and begins to consume the host’s marrow. The victim can make a DC 13 Constitution saving throw to resist the infection.

On a success, the marrow ooze escapes avoiding being destroyed by the host’s immune system. On a failure, the host is infected but actually feels better than ever. Infected creatures begin to look more attractive, and are healed of any bone deformities, bone conditions, or diseases of the blood.

Each day thereafter, an infected creature must make a DC 13 Constitution saving throw. On a failure, the host reduces their hit point maximum by 10, to a minimum of 1. Once the host has reached this minimum, the marrow ooze splits and horrifically transforms the host’s limbs into new marrow oozes in a process that resembles the melting of a piece of wax. The host is left without limbs, but their hit point maximum is restored.

These victims are at increased risk of developing a traumatic insanity.

A host that succeeds at two saving throws (they need not be consecutive) can expel the creature, though the expulsion process is painful and difficult.

Once the expulsion process begins, the host begins to bleed from every orifice and loses body fluids through violent and frequent body emissions.

This process reduces deals 2d6 piercing and 2d6 poison damage unless the host receives proper medical care (requiring a DC 15 Wisdom (Medicine) check). If a victim should die due to this violent process, their insides are liquefied, and 1d2 marrow oozes emerge from the body.