I found this cel on eBay (I've been searching a lot lately). The backgrounds often do not match the character pose on cels, as sellers aim to create a "scene" by Frankensteining them together. Eddy's pose looks like he's on a bed or in the Retro Van. As for the background, I have no idea. Anyone have some insight?
Edit: I found it! I had a hunch it was from "Dueling Eds," when Eddy was trying to avoid fighting Rolf.