"Gak! Cough! I just swallowed a bug."
Spiders of the moonlight, weaving webs of smoke, mist, and moonbeams.
Sometimes, someone is watching in the middle of the night.
Rats the size of cats, these insectivores are tree-top hunters. While they are useful to farmers and people, they are considered pests.
It is whispered at harvest bonfires that sometimes swarms will combine into a monstrously huge pile of Black Leaf Bugs, able to instantly stop anything it comes across. What is left explodes in a shower of maggots.
Not every prophecy needs to be meaningful to effect a game. In the Lord Dunsany play, The Golden Doom, a child's scrawl has an entire kingdom struggling to puzzle out what sinister prophecy it portends.