When the scientist Nathan Garrett was revealed to be a communist spy, he was forced to flee the US and ended up in the Balkans. There, he was inspired by a village statue of a winged horse to become the villain known as the Black Knight. Using his scientific knowledge, he mutated a horse using genetic engineering techniques that he had developed. The artificial mutations gave the horse large feathered wings and other special adaptations which enabled him to fly.[1]

After Garrett's final defeat by the original Iron Man, this winged horse escaped and eventually was further mutated and fell into the possession of the Dreadknight. In this incarnation, the steed was all black with a razor-barbed mane, sharp teeth, talons, a dragon-like tail, and leathery black wings similar to those of a bat. The Dreadknight employed the Hellhorse while attempting to wrest control of Castle Frankenstein from the Frankenstein Monster and the Children of the Damned