Earlier this evening, a clip purporting to be the Age of Ultron stinger scene was uploaded to YouTube.
It’s almost certainly a hoax, but man, is it well done. Whatever superfan put this together, I applaud you.
So, why is it fake?
Aside from the fact that Spider-Man is voiced (and thus cast)? Well, probably because Age of Ultron has no post-credits scene. Woops.