@niner No, as you do not hold all of the copyright - the legal argument is that fanart of a specific character is a derivative work of the original and therefore the copyright holder of the original character drawing(s) holds part of it.

If it wasn't that a severely limited subset of parody doesn't require copyright permission, you would be required to ask the copyright holder of the character drawing(s) for permission to legally draw fanart.

If you were to negotiate with the copyright holder, you could release the work under a license.