Z and I perfected a method of using masking tape to create a paintable surface for modified plastic toys (see our DIY Drawing Robot here for more details). We used this technique last weekend to transform a wind-up hopping Easter Bunny and a jiggling eyeball keychain into a pet monster that has been Z's constant companion ever since.
Wish we'd bought up a bunch of these wind-ups after Easter. I have a bunch of ideas.