I'm running a 5e game (actually using Into the Unknown rules set, but that's not important) using a whimsical Americana style setting that's pretty silly. Going for a feel like Unsleeping City from Dimension 20 but I've never lived in New York so its kind of the rest of America.
Anyway, the thread the players have been pulling on leads to a boss battle in the Appellation Mountains. Basically, a hillbilly big-bad has been making supernatural deals with people. Now that they're getting close, I need to decide if this bad guy is a devil or a he-hag. Both routes have a lot of potential, imagery-wise.