Chameleon (comics)
Created by writer Stan Lee and artist Steve Ditko, the character first appeared in "The Amazing Spider-Man" #1 (March 1963), making him the first member of Spider-Man's rogues' gallery, based on issue publication date, excluding the burglar who murdered Ben Parker (Supercharger was the first Spider-Man supervillain chronologically). He is also well known to be related to Kraven the Hunter. That revealed relationship helped evolve him as a major villain compared to his original depiction of being just a solo villain in the original issue of "The Amazing Spider-Man".
Flashpoint (comics)
The president announces Cyborg's failure to unite the world's superheroes and the U.S. enters into the Atlantean-Amazon war. Flash, Batman, Cyborg, and Element Woman break down the door in need of the Marvel Family's help and Batman asks Billy to use his lightning to prevent Flash's memories from changing even further. The group hears of the failed air assault on England due to the Amazons' Invisible Plane air force. Hal Jordan, who had not become Green Lantern in this timeline, is the first casualty, and a giant Atlantean-generated tidal wave threatens the rest of New Themyscira. Flash tells Batman that if he fails to stop Thawne, the world will destroy itself. Despite reservations, Batman joins Flash as the group heads off to New Themyscira. Enchantress joins them en route. Wonder Woman and Aquaman are fighting one-on-one until Flash and his team arrive.