Doing a 2e mini campaign set in Planescape's Sigil and I'm coming up with some side quest ideas to do in between the published modules. I'm setting up the players to get a quest from Parakk the Ratcatcher to do something for The Us (as this is mentioned under their entries in Uncaged that they can give quests to PCs), but I'm not sure what they would actually want the party to do.

FYI: The Us is an independent swarm of cranium rats who escaped the mental tyranny of Ilsensine iirc. Their ultimate goal is to take down the elder brain and "free" all of the cranium rats.

I was considering a quest to catch some cranium rats and bring them to The Us for conversion, but that's kind of what Parakk does (and he's really good at it, so not much reason to bring the PCs in to help). It should be something strange and can be a little dark too. The other side quest ideas I have are pretty much all faction-related so far.