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.
Juggernaut (comics)
The Juggernaut continues to feature prominently in Marvel titles, starring in an alternate universe adventure, battling Thor once again and starring opposite other characters such as the mutant team X-Force, Doctor Strange, the Hulk (allied at the time with master villain the Red Skull and tricking and capturing the Hulk with the same "civilian" guise used against Colossus), mercenary Deadpool, the villain turned antihero Venom, and multiple battles with the X-Men. The Juggernaut suffers a major setback during the "Onslaught" storyline, being defeated and then humiliated by the entity when imprisoned in the Gem of Cyttorak. The Juggernaut, however, eventually escapes.