Voiced by: Peter Onorati, Marc Worden (Justice League Unlimited)
Appearances: Batman Beyond | Justice League Unlimited
A half-human/half-Thanagarian hybrid that's a part of the future Justice League.
- Actually a Doombot: Seemingly killed by Superman at the end of "The Call" Part I, but he returns in the second part; he reveals that he actually remote-controlled his armor at the time of the explosion.
- Affirmative Action Legacy: Warhawk is the biracial son of John Stewart and Shayera Hol.
- Half-Human Hybrid: Half-human, half-Thanagarian.
- Luke, You Are My Father: To John Stewart and it was more like "Dad?"
- Power Armor: Which he can fly remotely.
- Razor Wings: Being the son of Hawkgirl, it's expected he'd take on this motif.
- Vitriolic Best Buds: Seems to have this relationship with Kai-Ro. The only time he smiles in the two-parter where he's introduced is when the young Green Lantern gives him a backhanded compliment. This could be a result of Rex being the son of the previous Green Lantern.
- Wolverine Claws: His armor has talons at the fingertips.
Appearances: Superman: The Animated Series | Batman Beyond | Justice League Unlimited
A god from Apokolips who's a current member of the future Justice League.See here for more info dealing with her in the rest of the DCAU.
- Action Girl: She was the best of the Female Furies and is from Apokolips. It's a give she's this.
- Battle Couple: Barda and Mr. Miracle during the second season of Justice League. In the Beyond comic, surviving after being thought dead after an attack by Ouroboros, Scott joins the League for real to join his spouse.
- Berserk Button: Do not call her pigheaded.
- Boom Stick: The Mega Rod, which fires powerful energy blasts that forced a possessed Superman to retreat.
- Hair-Trigger Temper: Particularly shown towards Batman/Terry.
- Magical Computer: The Mother Box, which opens up Boom Tubes.
- Mood-Swinger: She was very distrustful of Batman at first, but by the end of the second-part episode she sees him as a worthy teammate.
- Perpetual Frowner: Smiles every so often, but not a lot.
- Sky Surfing: With her aero-discs, she can glide in the air effortlessly.
- Statuesque Stunner: Just like her comic book counterpart, she is a tall beauty.
- Tiny Guy, Huge Girl: Barda and Mr. Miracle, one of the original pairs.
- Tsundere: She's not big on working with new people (Terry in "The Call," The Flash in JLU's "The Ties That Bind") without even being asked first, and is actually distrustful of Batman (Terry) when he joins them and immediately suspects him of being a traitor. She's a lot calmer around Mr. Miracle.
A young Tibetan that has donned the Green Lantern ring and a current member of the future Justice League.
- Acting Your Intellectual Age: He's far smarter than he looks, almost zen-like with his intelligence. In fact, he was raised as such and the monstrary he was raised in believed he may be the next Dalai Lama.
- Affirmative Action Legacy: John Stewart was an Afro-American marine while Kyle Rayner was Irish/Hispanic. Kai-Ro is a young Tibetian Monk.
- Battle Aura: Uusally has his green aura around him.
- Boring, but Practical: He's not flashy with his constructs, but he is very practical and gets the job done. It shows off his pratical nature along with reflecting the minimalistic tones of Buddhism he was likely raised in.
- Cain and Abel: Justice League Beyond Issue 21 delved into his backstory; it's revealed that he had an older adoptive sister whom he ended up parting ways with. Who was she? Curare.
- Flight: Via the Green Lantern Ring.
- Green Lantern Ring: Naturally, since he succeeds Jon Stewart.
- Heroic Willpower: He's a Green lantern after all.
- Levitating Lotus Position: He flies around this way.
- Not So Above It All: He once gave Rex a resounding Dope Slap via his ring after he made an insensitive comment.
- Wise Beyond Their Years: He is younger than Terry in his debut and had already been around the universe.
Appearances: Batman Beyond | Justice League Unlimited
Daughter of Aquaman who has taken her father's place in the future Justice League.
- Actor Allusion: A princess from an underwater society, voiced by Jodi Benson. Are we talking about Aquagirl, or Ariel?
- Affirmative Action Legacy: The daughter of Aquaman.
- Animal Talk: With marine life, anyway.
- Exposed to the Elements: Aquagirl was able to walk about in the arctic wearing nothing but a swimsuit.
- The Heart: Despite the circumstances of his joining, Aquagirl was friendly towards Batman (Terry). Overall she's less hotheaded than Barda and Warhawk, and more personable than Kai-Ro.
- Nice Girl: She is considerably nicer and more personable than her father (a rather Hot-Blooded Knight In Sour Armor) and is the first League member to begin warming up to Terry.
- Only Sane Man: When Superman came to the League for dating advice, Mareena is the only one to give a decent tip. The rest have varying suggestions that Supes believes are not exactly normal. Including the resident Battle Couple for some reason.
- Our Mermaids Are Different: Being Atlantean, she doesn't come with a mermaid's tail for starters.
- Walking Swimsuit Scene: Her uniform is nothing more than a tight black one-piece swimsuit.
Appearances: Batman Beyond
A superhero with the ability to change size. He's a member of the future Justice League.
- Affirmative Action Legacy: The African-American successor to The Atom.
- Big Damn Heroes: Despite being injured, he snuck up on Superman and battled him just long enough to save Terry.
- Chuck Cunningham Syndrome: Unlike the others, he never returns in the Justice League series not even for a cameo.
- No Name Given: Unlike the other members of the JLU, his real name is unknown.
- Size Shifter: He can grow and shrink.