I'll warn you that these are all Master Skins but they're the ones I'm familiar with:
Liquid, similar to Water, has an extra reflection blending/transparency option and a Night Sky reflection image in addition to Clouds:
https://www.wincustomize.com/explore/dream/search/Liquid/page/3
Moving Wallpaper, zooms, pans, and cycles a directory of images you choose:
https://www.wincustomize.com/explore/dream/3741/
Stars:
https://www.wincustomize.com/explore/dream/1617/
Desktop Collage (Doesn't actually let you pick the base background, uses its own, but you choose a directory of images for it to throw up there which covers up the background):
https://www.wincustomize.com/explore/dream/441/
I don't know of any rain, drops, or fog. I like the idea of fog, with some options similar to the Liquid Dream, I think that would be pretty cool.