Chameleon (comics)
The Chameleon was born a Soviet citizen named Dmitri Smerdyakov (Дмитрий Смердяков). In his youth, he was a servant and half-brother to Sergei Kravinoff and eventually became a minor associate to Gustav Fiers. Although Dmitri and Sergei were friends, Sergei was often abusive to Smerdyakov, leading to a combination of admiration and resentment towards Kravinoff. Eventually, Smerdyakov emigrated to the United States of America. As he had made a talent for himself during his youth, impressing his brother by impersonating friends and neighbors, he assumed an even more impressive disguise: the identity of Chameleon. During his first known criminal outing, he impersonated Spider-Man, though he was exposed and arrested. Shortly afterward, Kraven the Hunter himself came to America, and the Chameleon set his old associate's sights on Spider-Man. Both men became long-time enemies of Spider-Man, part of his primary rogues' gallery.
Uncanny X-Men
For the remainder of the decade the X-Men fight enemies such as Stephen Lang and his Sentinels, Magneto, Banshee's cousin Black Tom and the Juggernaut, the Shi'ar Erik the Red and the Imperial Guard, Arcade, Wolverine's former colleagues, Canadian superhero team Alpha Flight, and MacTaggert's son Proteus. In 2010, Comics Bulletin ranked Claremont and Byrne's run on "The X-Men" second on its list of the "Top 10 1970s Marvels".