purple watercolor art of flying bats in a misty forest background. concept of halloween, spooky atmosphere, night

halloween bats watercolor illustration art purple forest misty night spooky abstract painting watercolour aquarelle splashes dark eerie ghosts autumn seasonal haunted background creepy design scary mysterious nighttime moody woodland spectral clouds shadows foggy twilight phantoms horror fright gothic flying magic enchantments terror ethereal landscape banner backdrop wallpaper ai generated