Territory War

[Blink]

I am putting together a large cavern system dungeon for an extended crawl. Almost a mega dungeon which I'm hoping will take several sessions to complete.

One of the elements I want to include is an ongoing territory war between two monster factions within the caverns that the players can either get involved in, or try to avoid while exploring. I'm planning to have one side of the war be a colony of myconids who dwell in a heavily fungus infested section of the caverns. But I'm having trouble deciding what sort of monsters should be on the opposite side.

What would be a good natural enemy for myconids to be warring with?

[Kane0]

Something that breeds carrion crawlers, or something like that? I presume they’d be fighting over refuse that they would both need to ‘eat’

[loki_ragnarock]

Myconids vs. Otyugh

Mushrooms looking to spore on poop, Abberations looking to eat poop.

Now you just need a monster that poops enough to provide the resource for the conflict. Or they're fighting in the latrines that finally answer what happens to all the poop the monsters on the level above produced?

EDIT
Sorry, omitted the parts that make for an interesting dynamic:
Mushrooms are lower CR creatures that probably benefit from large numbers, Otyugh are higher CR creatures that there probably aren't as many of.

Both are capable of communicating, but their communication is *weird*.

Both are interested in a "treasure" the PCs don't want for themselves, so there's less risk of the PCs genociding everything to take it.