Steppenwolf first appeared in the comics in early 1972 with New Gods #7 by Jack Kirby. Kirby spent decades working in comics and many of those were for Marvel. His stint at DC lasted from 1972-1975, which is when he wrote 11 issues of New Gods. Steppenwolf is the uncle of Darkseid. As one of the New Gods, he was also a member of Darkseid’s Elite. He’s also the father of Fury, who doesn’t appear in the comics until 2013. In that iteration of continuity, Wonder Woman is her mother.
Based on what we know of the DCEU, it’s unlikely we’ll see Wonder Woman have Steppnwolf’s child, but it’s hard to rule anything out when it comes to superhero films and comics. When Steppenwolf was created, his character was in a very different continuity. His first appearance since the relaunch that DC Comics did with the New 52 continuity was Justice League #6 in 2012. So that’s the continuity in which Fury is his daughter.
During the Apokolips War, Steppenwolf led an army against Earth. His powers include superhuman strength, stamina, and durability. In the current continuity, there are two versions of Steppenwolf. One is on Prime Earth and the other is on Earth 2. The Steppenwolf that Jack Kirby created is totally different from the current one seen in the comics. With the way comic book continuity seems to continually change, it’s a bit hard to keep up. It’s even harder when DC throws the multiverse into the mix and you have multiples of every character.
In the current continuity Steppenwolf has already been killed and revived. Brutaal (a clone of Kal-El) is the one who does him in and unfortunately that wasn’t the last of him. Steppenwolf was brought back to life to fight in a war against the Anti-God, which, of course, was also for Darkseid. Steppenwolf is also known for having killed Wonder Woman and Superman in the comics when he led the army to Earth. With Wonder Woman 2 in the works already, there’s no way she’ll be killed off when facing him in Justice League. Plus, we already did the whole Superman-is-dead thing, so we don’t really need to do that again.
The character has made appearances in various animated shows. The first one he appeared in was Superman: The Animated Series, and he has subsequently appeared in Justice League, Batman: The Brave and the Bold, and Justice League Action. Steppenwolf is certainly a threat to anyone who stands in front of him. It’ll be interesting to see how the DCEU implements him in something other than his cameo in the Ultimate Edition of Batman v Superman: Dawn of Justice. In the meantime, check out the Justice League trailer and then go see the movie once it hits theaters on November 17th.