Lee and Kirby also produced the Avengers comic book, composed of Marvel's most prominent solo heroes at the time. Save for Captain America, Lee and Kirby eventually had all the Avengers leave to focus on their individual careers, replacing them with former villains from other comics who did not have a series of their own: the Scarlet Witch and Quicksilver from X-Men, and Hawkeye from Iron Man's adventures in Tales of Suspense. The team was known as "Cap's Kooky Quartet".DeFalco "1960s" in Gilbert (2008), p. 108: "[Stan Lee] replaced Thor, Iron Man, Giant-Man, and Wasp with Hawkeye, Quicksilver, and Scarlet Witch." Although common in later years, such a wide-scale change in the roster of a superhero group was completely unprecedented (usually, superhero teams only exchanged one or two members at a time rather than almost the entire roster at once). Lee and the following Avengers writer, Roy Thomas, hinted that other Avengers were romantically interested in the Scarlet Witch. The twins later leave the team after a crossover with the X-Men.
