I made a bunch of mushrooms that can be used for all sorts of Campaigns. These mushrooms have special traits and interact with the player, rather than just sitting there and growing. Most of them won't harm you unless you touch them.

1. Black Devil Mushroom: This is a dangerous mushroom that is found in the underworld. It doesn't move but is animated.
2. Devil Mushroom: Another underworld mushroom. Dangerous, and like the Black variant, it is animated but doesn't move.
3. Etherworld Mushroom: Yes, I notice only the Devil Mushrooms are actually somewhat of a threat to the player. Well, here you go then. A powerful mushroom capable of wielding powerful force energy to destroy an opponent.
4. Frostshroom: An arctic mushroom that can give a creature frostbite when touched.
5. Iron Eating Caveshroom: A mushroom found in mountains or caves. It eats at iron, usually ore, but could eat iron tools such as swords. Luckily, it eats slowly.
6. Lunar Gelshroom: I originally made this for another world, which is why it is so strange and powerful for an inanimate mushroom. You could use it for a magical creature's lair as a defense.
7. Mimic Mushroom: To give your party a scare, show them this mushroom. It looks like a poisonous spider. Probably put it in caves, maybe even by webs.
8. Stinging Waspshroom: This can be found anywhere, but rarely. It stings you when touched.
9. Stink Fungus: A classic stink gas mushroom. Probably for a swamp, jungle, cave, or marsh.
10. Tangle Fungus: Finally, a fungus besides the Devil Mushrooms that is actually somewhat threatening. The Tangle Fungus will grab you, and if it successfully grapples you it will start biting you with a small ring of teeth.
11. Whistling Mushroom: A mushroom that creates a small whistle when you walk near it. This can give your party quite a scare at first, as they may think it is the whistle of an approaching creature or some kind of attack signal.

Note: I am still very new to Challenge Rating, and it is probably very off. The stats may also be weird. I made the Devil and Black Devil Mushrooms when I first heard of dnd, so the Challenge Rating is probably way too high. Please give me advice on what to change the Challenge Rating to.

I hope you enjoy these mushrooms!

How fun to create things like that. 

Thanks. I'm new to dnd, but I'm very good at creating things.

Added the Etherworld Mushroom, because I wanted one that was threatening. This one is intense...

Thanks for sharing this content.

You're welcome. I can also make more.

I made the Mimic Mushroom

I always love seeing monsters and stuff that are not directly built for combat. They can make a world more interesting and believable. 

Yeah, that's why I made them. And nobody cares as much about making plants as other creatures, so here I am. Mushroom is forgotten even amongst plants, it's usually some kind of treee or something.

Yeah, I really wish there were more plant and mushroom statblocks. They seem to be overlooked, as well as oozes. 

Maybe I should make oozes next, there are very few of them.

Here, you may like this: https://www.dndbeyond.com/forums/dungeons-dragons-discussion/dungeon-masters-only/166130-i-made-the-forgotten-monsters-for-your-campaigns