Rex Stewart was the son of John Stewart, also known as Green Lantern, and Shayera Hol, id est Hawkgirl, two of the seven founding members of the Justice League. As the superhero Warhawk, Rex joined the Justice League Unlimited, the current Justice League of the 2040s.
Warkawk made his debut on the animated series Batman Beyond, and later appeared in Justice League Unlimited.
He is voiced by Peter Onorati, who voiced Robot Man in Teen Titans.
Warhawk was, at first, not impressed when Superman brought Batman into the JLU to seek out who had ambushed Micron. This only worsened when Batman could only barely prevent an assault on Aquagirl. But Warhawk was not stupid - he knew that whoever betrayed the JLU would come after him at some point. Warhawk remotely operated his armor into battle, and let the traitor destroy the armor.
Warhawk eventually helped Batman uncover the real traitor - a Starro-controlled Superman.
Justice League Unlimited
The Once and Future Thing
Following his humiliation at the hands of his wife and the experiences in the Old West, time-traveller David Clinton went mad with power and decided to use his technology for his own gain. To that end he retuned to the future of the 2040s and asumed the identity of Gotham City's new ruler Lord Chronos. He began appropriating historical buildings from the past and advanced weaponry from the future which he outfitted on a gang of Jokerz and had them sent to assassinate the JLU, sans Warhawk, Batman/Terry McGinnis and Static, who had managed to escape and took refuge in the abandoned Hamilton Hill High School. Green Lantern/John Stewart, Batman/Bruce Wayne and Wonder Woman, who had also been stuck in the Old West beacuse of Clinton, followed the time-traveller to the future in order to bring him to justice. They arrived after Clinton had established himself as Lord Chronos and were forst to team-up with the remaining JLU in hopes of victory. Green Lantern was shocked to discover that he and Hawkgirl would produce a son together, considering that they had broken-up following Hawkgirl's betrayel of the Justice League during the Thanagarian Invasion of Earth. Nontheless, Lantern worked with Warhawk without any reservation during their final fight against Chronos. Lantern rescues his son from almost being crushed to death and even encourages Rex to fight on despite the situations. After Batman and Green Lantern stop Chronos from travelling back to the beginning of time and rewritting history so that Chronos could become a god, the two heroes are sent back just before they had med Chronos, with Batman having installed a failsafe device on Chronos to ensure that none of the time-travelling events will never have accoured. Despite having saved the universe, Batman and Lantern retained their memories of all that had transpired. Realizing that Warhawk was his and Shayera's son, Lantern can't help but worry about his and Hawkgirl's destiny.
Warhawk, alongside fellow JLU members: Green Lantern and Aquagirl, made a brief appearance in an imaginary fight against the Iniquity Collective, comprised of Inque, Stalker, Shriek and Parasite II. Warhawk knocks out Parasite with a single punch while his colleagues take down Inque and Stalker. Shriek is defeated after Batman shows up and destroys Shreik's hand held sound generaters. Warhawk and the rest of the League are shocked to hear that Terry is resigning from the JLU, but none of these events actually accured since the entire fight was only part of Terry's fears as to what will happen following the revelation behind his secret origins and his true relationship to Bruce Wayne.
Shadow of the Hawk and Ancient History
When archaeologist Cartel Hall begins dating Shayera, and more importantly, claims to be her lover in a past life, Green Lantern becomes devastated, believing more then ever that he and Shayara must be ment to be together. The situation only escalated further after the supervillain Shadow Thief proves Carter's theory to be true. Carter and Shayara were once two Thanagarian law officers (Katar an Shayara Hol) who crashed in Ancient Egypt sometime during 6000 B.C. They used their knowledge to uplift the people there and became their rulers. As it also turned out, Stewart was once a human general in Katar's army who had an affair with Shayara, which tragically resulted in all three of their deaths. After Cartel/Hawkman defeats Shadow Thief, he decides to leave Hawkgirl and Lantern alone, contempt with the knowledge that he was never Shayara's true love. However, even after Lantern reveals to Hawkgirl the eventual existence of Warhawk in the future, he still refuses to allow fate to dictate his path in life and chooses to stay with Vixen until he chose otherwise.
- Warhawk's first name, Rex, was likely named after Rex Mason, also known as the superhero Metamorpho, who was John Stewart's close friend during his time in the marine corps and later the expanded Justice League.
- Before his connection to Green Lantern was ever established, Warhawk's face was never shown behind his helmet. At the time of the production of Justice League Unlimited, Warhwak's face was modelled after Stewart's.
- A sixtyfive year old Static claimed that Shayara had given birth to Rex through an egg, however Rex said that this was all a joke on Static's part.
- Warhawk was voiced by Peter Onorati.
- Unlike Green Lantern meeting his son in the future, Batman seemed to take meeting Terry McGinnis without any trouble. However unlike Warhawk, Terry never unmasked himself in front of the time-travelling Batman/Bruce Wayne, nor did Bruce allow himself to be taken in by the future. And as such, Bruce and Terry's inevitable meeting in the future was not effected in any considerable way.