Cancer

Crawling out of the Silver Age in The Avengers #72 (1970) — courtesy of the legendary Roy Thomas and Sal Buscema — Cancer is a Marvel creation steeped in that era's bold, imaginative storytelling. With a name drawn straight from the zodiac, this character keeps striking company alongside the likes of Leo, Taurus, Sagittarius, Virgo, and Aquarius, suggesting a cosmic, sign-themed corner of the Marvel Universe that collectors have long found irresistible. Two of Cancer's appearances carry key-issue status, making even a slim seven-issue catalog punch well above its weight. For fans of deep-cut Marvel lore and the Avengers' rich Silver Age mythology, Cancer is exactly the kind of hidden gem that makes digging through back issues so rewarding.