Warning: The following contains spoilers for Supergirl: Woman of Tomorrow #8, on sale now from DC Comics.
Supergirl: Woman of Tomorrow #8 (by Tom King, Bilquis Evely, Matheus Lopes, and Clayton Cowles) shows a terrible fate for Supergirl's super-horse Comet, but in his last moments, his original form as the centaur reasserts itself before Kara's eyes. Comet’s history is strange as is his relationship with Supergirl over the years. This final act of sacrifice is reflective of their relationship and his committed love for her.
In the final issue of King’s take on Supergirl, Comet sacrifices his life to save Kara’s. In the moment of his death, he transforms back to a centaur, staring at Kara as he does so. Later, she brings his dead body to the beach where her companion Ruthye waits, alongside the notorious Krem of the Yellow Hills.
Comet has two different histories. Prior to the initial Crisis on Infinite Earths, Comet’s origin was incredibly convoluted. Created by Leo Dorfman and Jim Mooney, Comet was originally introduced in 1962 in Adventure Comics #292 and revealed to originally be a centaur named Biron in ancient Greece. Biron sought the assistance of the sorceress Circe (long-time nemesis of Wonder Woman) and she transformed him into a horse accidentally, rather than turning him into a man. She immediately felt guilty and so imbued him with super-abilities.
Years later, exploring space on his own (as flying horses tend to do), Comet sees Supergirl and assists her in foiling an alien invasion of Earth. Supergirl, known as Linda in her human disguise has dreams of Comet over and over until she later travels to a ranch and meets him in real life. Comet reveals his telepathy and that he was pushing the dreams to Supergirl, hoping to draw her to him. Later, it was revealed that he had the ability to transform back into a human, but only when a comet passed nearby in space. As a human, his identity was as the rodeo star Bronco Bill Starr. Supergirl fell deeply in love with him in his human form. Yes, this was all pre-Crisis canon. Comet’s love for Kara was there from the beginning. He once pondered, “If I were a man . . . If I were free to tell her of my real feelings, for a girl like that, I’d even give up all my super-powers!”
Later, Peter David and Leonard Kirk introduced a completely new origin in Supergirl #14 (October 1997). In this version, Comet was originally a jockey named Andrew Jones who had been rebuilt to have the abilities of a horse. Breaking free from the group that remade him (the Stable), Comet began working as a superhero. The story becomes incredibly convoluted at this point as he dies and then merges with a girl named Andrea Martinez. Kara falls in love with him but ultimately she ends the relationship. Later, Comet is given a full transformation into a winged centaur. David’s story presents a detailed story on gender and discrimination—Andrea was a young woman navigating her sexual identity, a failed marriage, and rejection by her parents.
Oddly, Kara isn’t the only DC hero harboring feelings for Comet. The Flash #61 revealed that Zebra-Man has hidden passions for the superhorse. At one point, pre-Crisis, Comet even has a brief relationship with Lois Lane.
The current version of Comet that has been accompanying Kara in her adventures through space in Supergirl: Woman of Tomorrow is not the Andrew Jones version. Having no wings, Comet’s appearance resembles the pre-Crisis origin. In this issue, Kara confirms it: “That’s . . . That was Comet. He was a man . . . He was cursed . . . To be in the body of a horse . . . It’s complicated. He didn’t like to tell people about it. He told me because he loved . . .” She doesn’t finish her sentence but the implication is that Comet told her because he loved her, confirming that this is the original Comet, the former centaur Biron, who was more than just Kara’s horse but truly her first love.