Cottonmouth

Cottonmouth slithered onto the scene in 1985's Captain America #310 — a Bronze Age Marvel debut courtesy of Mark Gruenwald and Paul Neary — and has been a fixture of the serpentine underworld ever since. A card-carrying member of both the Serpent Society and A.I.M., this villain runs with a genuinely dangerous crowd, sharing panels with the likes of Anaconda and Rattler across nearly four decades of Marvel history. Most at home in the pages of Captain America, Black Panther, and Battle Scars, Cottonmouth has racked up two collector-significant key appearances across 29 catalog appearances spanning all the way to 2025 — a testament to the character's stubborn staying power. If you love Marvel's criminal ecosystem and the Bronze Age villains who helped define it, Cottonmouth is absolutely worth tracking down.