I know that Marvel has said he isn't, heck, his tagline was Greatest non Muntant super hero during the Nineties after all! But, wouldn't it be a fun story for Spidey to figure out he actually is a secret mutant? With his mystic background where he was always destined to be Spider-Man, I think you can consider him a mutant. For the Science background story, I think theres a way he could still be a mutant. Nowadays, radioactivity is used in radiotherapy to cure cancer. Maybe when the radioactive spider bit Peter, it didn't transfer powers, the radioactivity caused mutant genes to kickstart all of a sudden, in a way to help build Peter's body, and immune system.
Could Spider-Man actually be a mutant?
Nope Peter's not a mutant in fact i've noticed recently he's starting to bear similarities to the Black Tarantula. Both of them are Spider-totems, both of them where "chosen" to bear its powers (Peter via whatever the hell chooses Spider-people and Black Tarantula via his bloodline) and both of their abilities seem to improve the older they get (Peter shedding his skin and gaining the "other" powers and Black Tarantula going from a 25 to an 85 tonner due to his age).
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