My entry for Support KIRA's challenge 'Nighttime Fancy'. It's not the best I could have done, so I'll probably post another one...but I don't think it's terrible.
I picked this scan, which can be found here, because when I think of nighttime, I think of mythical creatures like elves and unicorns (also the horror creatures, like vampires, demons, monsters, and werewolves, but that's off topic), and usually when I think of nighttime activity, it usually occurs in a forest. That's why the wallpaper is an elf holding a unicorn w/trees in the background (or at least silhouettes of trees).
Hope you like!