Fungi, Mulcher 2014
CR 6 plant
Gargantuan plant, unaligned
When exposed central stalk can be attacked and destroyed (AC 13; hp 50; vulnerability to acid cold and fire). If central stalk is destroyed mulcher has disadvantage on attacks and can’t use Expose Stalk until it regrows one at end of next long rest.
Ground within 20' is difficult.
If it burrows 20'+ straight toward a creature can dig 10 ft. diameter 20' deep pit beneath it. Each Large or smaller creature in pit’s area: fall into mycelium-lined pit and land prone taking 14 (4d6) piercing damage from spiked mycelium + fall damage (DC 15 Dex doesn't fall). Can make one Mycelium Spike vs. prone creature in pit as bonus action.
Gains 15 hp at start of its turn if it has at least 1 hp.
Bonus Actions
Exposes central stalk above ground until end of its next turn or until it ends effect as bonus action. If exposed can't burrow.
Burrows up to 60 feet. Opportunity attacks vs. it are made with disadvantage when mulcher burrows out of an enemy's reach this way. Creatures grappled by it are freed before it burrows.
Reactions
When reduced below half hp max or creature scores critical hit vs. it immediately uses Expose Stalk.
Source: Tome of Beasts 3 (Kobold Press) · License: OPEN GAME LICENSE Version 1.0a details