"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.
Under the sewers of a large town ancient burial chambers are discovered. If the PCs investigate they fill find that a pale white flowers grows amongst the graves, in the dark.
How do they survive without light? What is their origin? Why in a burial chamber and not just in any old cave?
Can they be sold or do they have any special quality at all? It is up to the PCs to discover.