First appearance: Web of Spider-Man #118 (1994)
Oh, yes, the ‘90s were bad for Spider-Man, and the low-light of the decade came during the “Clone Saga” when Marvel thought it was necessary to introduce us to the Scarlet Spider. He was a clone of Spider-Man who went under the name Ben Reilly; for a time, Reilly was considered to be the real deal and Peter Parker was the imposter. Thankfully, that all got straightened out and the Scarlet Spider was soon killed off.
It’s hard enough to get Spider-Man right in a movie, but having a clone running around in his own series would just be madness. Fortunately, it's difficult to imagine anyone in Hollywood actually going through with anything as ridiculous as this. Then again, Collin Farrell was once cast as Alexander the Great, so anything is possible.