Spore Body Elixir, a Potion for 5e

Spore Body Elixir

Potion, uncommon

Suspended in this thick, chalky potion is a living puffball mushroom. When you drink this potion your body transforms into a cloud of fungal spores for 10 minutes. You can end this effect as a bonus action.

While in spore form you can't speak, manipulate objects, cast spells, or make conventional attacks. You are weightless, have a flying speed of 20 feet, can hover, and can enter a hostile creature's space and stop there. In addition, if air can pass through a space, you can do so without squeezing, and you can’t pass through water. You have advantage on Strength, Dexterity, and Constitution saving throws, and you are immune to all nonmagical damage, except for fire damage, necrotic, and psychic damage. While in spore form you can make a special choking spore attack, and you can make a choking spore attack against a creature that starts its turn in your space as a reaction.

Choking Spore Attack. A creature in your space must succeed at a DC 15 + your Con modifier Constitution saving throw or take 7 (2d6) poison damage. Creatures that do not breath cannot be targeted by this attack. If you are a myconid or other plant creature your target has disadvantage on their saving throw.

When consumed by a myconid a spore body elixir’s duration increases to 1 hour and if the effect is ended prematurely the myconid can resume the effect as a bonus action.