LogFAQs > #961475031

Iirc, the story goes that Stan Lee's editor asked for a new hero. While Stan was sketching up some concepts, he saw a fly or spider on the wall and had this idea to make a hero based around a spider. This is a cool idea because the concept of associating spiders with heroes was kind of classic, if not lost on the current audience, and there had developed trend of associating mammals with heroes those days instead. So, when Stan took the idea to his editor
...... His editor hated it. Said nobody would take it seriously. Said it was gross.

Stan Lee was so put off by the experience that he redesigned "Spider-Man" to the best of his ability and lobbied to get him his own series.

It was an instant hit

Iirc