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,