4-D

Emerging from the pages of Grant Morrison and Howard Porter's landmark JLA run in 1998, 4-D is one of those intriguing figures who flickers briefly but memorably through DC's modern era. With only a handful of catalog appearances, this character is the very definition of a deep-cut discovery — a rare presence in the world of the Justice League's greatest stories. Sharing pages with titans like Wonder Woman, The Flash, and Plastic Man, 4-D exists in genuinely rarefied company, making those few appearances all the more worth tracking down for the dedicated collector.