Festerwood Fungal Stave (Patreon)

Staff, very rare (requires attunement by a cleric, druid, or sorcerer)

This fungal staff has 25 charges and regains 1d10+15 expended charges each day at dusk. While holding the staff, you can expend 1 or more charges as an action to cause clusters of noxious mushrooms to magically appear in a number of unoccupied spaces equal to the number of charges you expend. The spaces must be on solid ground and within 60 feet of you. Each space becomes difficult terrain for the duration. When a creature moves into or within an space or area with these mushrooms, it takes 2d4 poison damage for every 5 feet it travels. The mushrooms live for 1 minute or until you dismiss them early (no action required).

In addition, while holding the staff, you can expend 1 or more charges to cast one of the following spells from it, using your spell save DC: cloudkill (5 charges), fog cloud (1 charge), insect plague (5 charges), or stinking cloud (3 charges). These spells are cast using a bonus action instead of their normal casting time and must target a point adjacent to a space occupied by the mushrooms. In addition, these spells' duration becomes 1 round instead of their normal duration, ending at the end of your next turn, and do not require concentration.

If you expend the last charge from the staff, roll a d20. On a 1, the staff begins to violently overgrow, forcing you to drop it in an unoccupied space adjacent to you. If the staff is dropped on solid ground, a violet fungus (Monster Manual p. 138) grows in its place.

The festerwood's deep moss hides its ravenous flora. The carcasses in the woods are quickly pulled deeper into the undergrowth, feeding its unique breed of parasitic fungi. While you may think yourself alone in the festerwood: you are never safe.