Heck, just sticking to Wickerbottom alone I'm already pretty engaged building farms with mobs. Pigs, Grass Geckos, Butterflies, Catcoons, Bees, Lureplants on boats (lol).
I was kind of looking for a way to make Bee Boxes produce full speed (within 20 tiles, I think) but not hover all over camp. Sad to find they fly over fences/walls.
Anyone have some other "farm" ideas using mobs for some automation?