Klaatu

A creature of the early Bronze Age, Klaatu made their Marvel debut in the pages of The Incredible Hulk #137 in 1971, brought to life by the formidable creative trio of Roy Thomas, Gerry Conway, and Herb Trimpe. The company this character keeps is genuinely impressive — sharing pages with Bruce Banner and the Hulk himself, the Abomination, and even Doctor Strange — which speaks to the cosmic and chaotic corners of the Marvel Universe Klaatu inhabits. Rare in catalog count but spanning a surprisingly wide stretch of publishing history from 1971 to 2005, Klaatu is the kind of deep-cut Bronze Age curiosity that rewards the dedicated Hulk completist hunting through the back-issue bins.