Dr. Diehard

A menacing presence born from DC's early 1990s landscape, Dr. Diehard made his mark in Justice League Europe #15 (1990), conjured by the creative powerhouse trio of Keith Giffen, Gerard Jones, and Bart Sears. His brief but memorable run places him in dark, charged company — sharing pages with the likes of Lord Havok, Tracer, and Gorgon, a rogues' gallery that signals he's no ordinary antagonist. Though his catalog footprint is small, spanning Justice League Europe and Justice League Quarterly, that rarity is part of the appeal — a Copper Age curio with a killer name that serious DC collectors will want to track down.