Saga of the Swamp Thing #21 (DC, 1984)

One of the most memorable Swampy covers from the 1980s, this issue is an absolute key, as it was new writer Alan Moore's second issue. Titled "The Anatomy Lesson", this story didn't just retell Swamp Thing's origin story, it essentially reinvented the character, markedly increasing his potential. The cover image harkens back to Swamp Thing's House of Mystery origins, and re-establishes his connection with horror comics. Such perfect covers to key stories very rarely come on the market -- and this marks the very first time this one has, as it has been buried in a collection for many decades.