Cute. I believe I see velcro on the right side of the picture holding the white "tux" part onto the black cloak. Pretty tolerant hedgie they've got there.
For a less-intrusive Halloween effect, I bought the Halloween-Decorated Kleenex boxes for my little guys houses. (in addition to their usual sleeping beds) Kleenex has some real cute ones that have the images that appear to "move" when the box moves. Decorative and my hedgies liked them! (I bought the short stand-up ones, not the rectangle ones) I plan to do this for other holidays as well now that I know they like them.
Check this out, we can design our own boxes! (should I have a desire to splurge a bit, heehee)