Elk is right, though I would say that saying "ok" or giving someone a go-ahead, even calling something a gift, doesn't hold up as legality in the IP world of selling & using ideas or content. That is, a contract which outlines the terms & agreements followed by an actual signature is generally what allows one to license something unless there was an exchange of money & direction in which case the property is considered a commission—and not a proprietary.
When you create something original, assuming it is tangibly specific and considered an elaborate concept or creation, it is inherently copyrighted. You can register copyrights with the bureau for added protection; it runs about $30 and takes an hour or so to fill out, then usually a couple weeks or months to get approved.