This interesting, and even slightly useful, website combines the various layers that the cult classic SNES JRPG Earthbound uses to construct its funky battle backgrounds. There are more combinations here than actually appear in the game. There is a GIF-making function, but it seems to be broken for the moment. You can still make them full-screen and save screenshots, that’s what I did, though unfortunately doing it that way means they aren’t animated.
Here are a few still examples.
Earthbound Battle Backgrounds (a bona-fide website!)