10 Insane Superman Crossovers You Won't Believe Exist

By the 1970s, Superman had been in one-off crossovers that featured real-life celebrities from that era, but none of them can hold a candle to the time the Last Son of Krypton went toe-to-toe with one of the most influential sports figures of all time, Muhammad Ali.

The story features Superman and Ali entering an intergalactic contest in an attempt to save the Earth from destruction at the hands of the alien Scrubb, a species that was disgusted by humanity's unruly nature.

Both men wish to fight on Earth's behalf but the contest will only allow of them, leading to the Man of Steel and the Greatest engaging in a boxing match under the red sun, a fight that Superman is trounced in due to his lack of proper fighting experience. However, due to the heroes' valiant efforts, the Earth is spared from destruction.

The comic was a role call of DC heroes and American public figures and cast Ali in a very positive light, showing that his larger-than-life persona could match up to Superman's otherworldly nature and the story, despite its premise, is a summary of what makes the heroes towering and timeless icons of any era.