Reminds me: In the roguelike game Cataclysm DDA, there's fungus monsters. Basically once they're on the map, the best strategy was to just run and keep running until they were out of the game's "simulation bubble."

They would spread fungal colonies uncontrollably, creating fungal towers, spawning more spores, and fungal versions of monsters, which would spread more spores...

You could hack away at them or burn them sure, but all of them? Unlikely. You could also get infected with spores! They'd rapidly take over the entire game basically lol ... Dunno if that's been nerfed now.

Spores are freaky. Really freaky...