Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4604775.

This is a lithophane that can be lit with your Christmas lights. Shown here just hanging on the light but you should put a hook in it to hold it better to a branch then drop in a light. You can even use differed color lights to get different effects. I printed this with a brim 6 mm wide no supports.