Grey Fungus (5e Creature)
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Medium plant, neutral evil
Slam. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 6 (1d8 + 1) bludgeoning damage, and the target has to succeed on a DC 13 Constitution saving throw against becoming infected with grey fungus spores. On a failed save, the creature is infected and poisoned. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is poisoned for 1 hour and will remain infected until cured with lesser restoration or similar magic. If an infected creature is killed, it rises as a grey fungus 24 hours later, unless the creature is restored to life or its body is destroyed.
The grey fungus is a slimy fungus that overgrows all kinds of surfaces. Creatures that are exposed to the fungus risk being infected by its spores and starts mutating slowly. Beings that die this way will rise as an anthropomorphic fungus with the desire of further spreading the grey fungus. From William Hope Hodgson, "The Voice in the Night", 1907.