Every other week, marvel_gen will have a fanworks challenge. Unless specified, there is no time limit, or minimum required word count for responses. These are basically designed to generate flashfic, flashart, and flash-whatever-you-want-to-make. IE. Moar Marvel Gen!
This week's prompt is:
You can respond to the challenge at any time. Fic, art, fan comics, and vids are all welcome. Please tag your responses with 'prompt: winter'.