Back in 1960's Brave and the Bold #28, several superheroes banded together to battle a giant, purple, psychic, cycloptic, alien starfish (because that is daily life in comics).
Upon the creature's defeat, the heroes of Earth realised that because they worked together so well, they formed an official team called the Justice League.
At some point, nearly every DC superhero (and a few supervillains) have joined the team's ranks. Over the years, they have protected the world, the galaxy, and the multiverse from every conceivable threat including immortals, gods, and people who dress up as playing cards (those guys are the worst).
Now, you'll struggle to find a single person who doesn't know members of the League like the Flash, Superman, or Wonder Woman, but a lot of people aren't up to speed with the JLA's enemies. Before the Justice League film was released (the first time), very few people had heard of Steppenwolf.
If you're familiar with the comics and the animated series, you should recognise most of the Justice League villains on this quiz. But only the best of the best will be able to guess every single one of them right.