If you watched the Superman teaser trailer and thought, Wait, Superman has a dog now?, yes: The Man of Steel has had a furry best friend, Krypto, since 1955. The red-caped white dog has just been left out of many Superman stories, on account of being kind of silly.

The inclusion of Krypto in the new film — like every decision surrounding Superman — has, believe it or not, some serious stakes. Superman director James Gunn, who co-leads DC Studios, has said the future of DC films will depend in part on how audiences receive his new take on Superman, which arrives in theaters July 11, 2025.

When Superman, created by writer Jerry Siegel and artist Joe Shuster, first debuted in Action Comics #1 in 1938, he did not have a dog. He was, as we all know, just a simple alien blasted from the planet Krypton, who crash-landed on earth, where he was raised by Jonathan and Martha Kent. He grew up as Clark Kent, the identity he maintains when he isn’t Superman.

Given the success of Superman, Detective Comics (as DC was then known) decided in 1944 to start publishing stories about his youth, in order to appeal to younger readers. The Superboy stories featured tales of Superman in his preteen and teen years.

Krypto in the Superman teaser trailer. Warner Bros.

Krypto’s first appearance was in a Superboy adventure story in Adventure Comics #210, in March 1955. The dog, originally intended as a one-off by writer Otto Binder and artist Curt Swan, quickly gained a following, and became a regular part of Superboy’s world.

Since then, the flying pup has popped up in many super stories, and has had a big resurgence in popularity this century. He got his own animated series in 2005, 50 years after his Adventure Comics debut, and subsequently appeared on the WB and CW series Smallville, the HBO Max series Titans, the animated 2022 film DC League of Super-Pets — in which he was voiced by Dwayne Johnson — and in CW’s Superman & Lois.

He was left out of the original late 1970s and ’80s Superman films, starring Christopher Reeve — perhaps because comic-book movies were less common in the era, and a flying dog seemed like a little much for directors still trying to convince audiences that a man could fly.

Krypto was also left out of Bryan Singer’s 2006 Superman Returns, and Zack Snyder’s darker incarnations of Superman in Man of Steel, Batman v Superman, and Snyder’s version of Justice League. A cute dog just wouldn’t have fit the super seriousness of the Snyderverse.

Krypto in the Superman Teaser Trailer

But Krypto will get perhaps his best moment in the sun with the 2025 Superman, if Thursday’s new Superman teaser trailer is any indication. It prominently features Krypto not only demonstrating his super speed, but coming to the rescue of David Corenswet’s new Superman, literally licking his wounds as he lies facedown in the snow.

“Take me home,” Superman says to his dog, as the little guy seizes his superhuman’s cape in his jaws.

But Krypto isn’t just there for comic relief or to prop up the Man of Steel. At a press conference about the Superman teaser trailer, writer-director James Gunn promised the super canine will have a multifaceted personality (like all dogs do):

“His relationship with Krypto is complicated,” Gunn said. “He’s not nearly the best dog. There’s a lot more to Krypto than you see in this trailer.”

In some ways, the animal mirrors Gunn’s own dog, Ozu.

“Krypto was inspired by our dog Ozu, who we adopted shortly after I started writing Superman,” Gunn tweeted in October. “Ozu, who came from a hoarding situation in a backyard with 60 other dogs & never knew human beings, was problematic to say the least. He immediately came in & destroyed our home, our shoes, our furniture – he even ate my laptop.

“It took a long time before he would even let us touch him. I remember thinking, ‘Gosh, how difficult would life be if Ozu had superpowers?’ — and thus Krypto came into the script & changed the shape of the story as Ozu was changing my life.”

Gunn noted that he was introducing Ozu to the world during Adopt a Shelter Dog Month, adding: “Btw, Ozu today, is, fairly often, a very good boy. “

What Kind of Dog Is Krypto?

As Gunn has noted, Krypto has resembled many different breeds over the years. But his breed doesn’t matter.

When Gunn introduced Ozu to the world, one fan questioned whether he was an appropriate model: “Not to be ‘that guy,’ but isn’t Krypto supposed to be something akin of a Labrador or something similar?” the fan asked.

Gunn responded by dropping some comic book knowledge, and also confirming that Krypto, like Superman, is from Krypton.

“No,” Gunn replied. “Krypto is a generic white dog, sometimes a Lab, white shepherd, husky, or Dalmation. But obviously he’s an alien so he wouldn’t necessarily be exactly any one of those things.”