When most people hear the name Steppenwolf, they think about the rock band by that name with the hit songs "Born to be Wild" and "Magic Carpet Ride." Unless, of course, you're a big theater fan, in which case you likely think of the successful Chicago theater company named. And, okay, some Hermann Hesse fans think of his 1927 novel of the same name, which actually inspired both the band and the theater company. However, very soon the name will be associated first and foremost with the "Justice League" movie, because the main villain of the upcoming film is none other than: Steppenwolf!
With his warrior background, his power from being from Apokolips and his military cunning, Steppenwolf should be a great initial villain for the Justice League. His involvement was first rumored a while back and there was also a deleted scene in "Batman v Superman: Dawn of Justice" that looked to involve Steppenwolf.
Steppenwolf (German for "wolf of the steppe" -- basically a coyote) made his debut in the classic seventh issue of Jack Kirby's original "New Gods" series in 1971 (Kirby was inked by Mike Royer in the issue). Titled "The Pact," the story explained how the great alien worlds New Genesis and Apokolips came to be at war with each other. You see, young Darkseid and his uncle Steppenwolf, the greatest warrior in Apokolips, came across the New Genesis leader Izaya and his bride, Avia. After a brief scuffle, Steppenwolf accidentally killed Avia. Izaya was in a rage, but Darkseid stepped in and seemingly killed Izaya.
In reality, Darkseid only stunned Izaya enough to make him appear to be dead. Darkseid knew that when Izaya awoke, he would declare war on Apokolips, wanting vengeance on Darkseid's uncle Steppenwolf in particular. That's exactly what happened when Izaya later met Steppenwolf in battle.
Izaya eventualy managed to get over the great hatred in his heart with the help of The Source (the non-religious consciousness/guiding force of the DC Universe), transforming himself into the peace-loving Highfather. He and Darkseid made a pact to end hostilities between the two worlds. Highfather would give over his son, Scott Free, to Apokolips and Darkseid would give over his son, Orion, to New Genesis. Darkseid did this knowing that one day Scott Free was going to escape from captivity and thus negate the pact, but by this time, Darkseid would be fully in control of Apokolips. That's precisely what happened.