Everyone in Earth-Eight: Men of Metal

Just as Superman was the harbinger of supers in spandex, his counterpart on Earth-Eight was likewise... albeit ever so briefly.

Arn Munro was raised by his mother, never knowing his father Hugo Danner who had gone missing decades ago. Turns out, Hugo's father (and Arn's grandfather) injected his pregnant wife with an experimental drug which imbued his soon-to-be-son with super-human strength, speed, and nigh-invulnerability.

These same traits were based down to Arn, who unlike his father had not become disillusioned with humanity. Thus rather than seek retreat in a tropical jungle like his sire, Arn soon drew the attention of not only the public-at-large but his fellow teen titans. Joining alongside fellow superhumans, the lad adopted the alias Iron Munro and admirably built a modest legend in comparison to his more colorful contemporary across the cosmos.

How, though, can we say with certainty that this hero originated on Earth-Eight? Well, writer Roy Thomas mentioned how the Young All-Stars absorbed the energy left over by heroes that ceased to exist during the 1940's, including the golden age Superman. It was revealed during the Infinite Crisis by Alex Luthor of Earth-Three that the potential Earth-Eight was where all remaining characters originated that had not previously appeared on former Earths known as Earth-One, Two, Four, S or X. Their adventures on that merged post-Crisis Earth would have mirrored those on Earth-Eight.