This was done because in my fan fiction series the world of Supernatural exists alongside the world of Charmed with characters popping up now and again from there.
This opening credits features the Winchester boys and John during the first season of my fan fiction series and afterwards also until Supernatural season 4 minus John and so would be shown instead of the main credits when they're in a story.
This was made solely for entertainment purposes and non-profit gain.
And I do not own Charmed or Supernatural of course as they belong to Eric Kripe/MC G Productions plus Aaron Spelling Productions although I do own Melissa.