Chameleon  (introduced in  The Amazing Spider-Man  #1, March 1963), the  Vulture  (#2, May 1963),  Doctor Octopus  (#3, July 1963), the  Sandman  (#4, Sept. 1963), the  Lizard  (#6, Nov. 1963),  Electro  (#9, Feb. 1964),  Mysterio  (#13, June 1964), the  Green Goblin  (#14, July 1964),  Kraven the Hunter  (#15, Aug. 1964),the  Scorpion  (#20,