WARNING: This article includes SPOILERS from Superman.James Gunn explains Milly Alcock’s Supergirl debut in the DC Universe through the Superman movie. One of the biggest Superman movie references and Easter eggs was the House of El, as fans not only got a glimpse of Kal-El’s birth parents, but his famous Kryptonian cousin, Kara Zor-El, a.k.a. Supergirl.

Towards the Superman movie ending, a very drunk Kara shows up at the Fortress of Solitude to pick up Krypto, revealing that it was actually her dog. While Alcock’s cameo became one of the fun surprises in Superman, the DCU is just getting started with her, as the Supergirl film will be arriving in 2026.

In an interview with Entertainment Weekly, Gunn shared more about Alcock’s Supergirl cameo and how it was used as a way to give the DCU audience an introduction to the Girl of Steel. Gunn stressed that it was important to have Supergirl at the end, as he shared the following:

James Gunn: But for me, the main reason for Kara showing up is to show that Superman not only risked his life to go save a dog that was his dog, that so many of us would do, he was watching the dog for somebody else. The dog’s a pain in his ᴀss. He didn’t want to take that dog. She’s off being irresponsible. He doesn’t want to have to watch a dog. He’s having to save the world every two seconds. And even still, he goes to the ends of the earth for that dog.

To me, that’s one of the most touching things in the movie. Earlier, when Lois says, “It’s just a dog,” and he says, “Yeah, not even a very good one, but it’s probably scared,” it just shows you the depths of his empathy. I find that so touching. Then, when you find out at the end, it’s not even his dog; she just left it with him.

Alcock’s Supergirl movie is set to release in theaters on June 26, 2026, directed by Craig Gillespie, based on a script from Ana Nogueira. The Supergirl film will also star Jason Momoa as Lobo, Matthias Schoenaerts as Krem of the Yellow Hills, and Eve Ridley as Ruthye Marye Knoll.

What James Gunn’s Supergirl Comments Mean

Having Supergirl appear in Superman was not only a way to finally get the Kryptonian cousins to share the big screen together for the first time, but also an opportunity to give a taste of how different they are as characters. But as Gunn also explained, the story is allowed to show Clark’s care for Krypto and Kara, even if he wasn’t necessarily looking to be doing dog-sitting.

While it was brief, Alcock’s cameo was a perfect opportunity to give a preview of Supergirl and Krypto’s dynamic, especially as they head into her solo film in 2026. With the DCU’s Supergirl setup, the audience now also has a good idea of Kara’s relationship with Krypto, as there is now a foundation between the two of them in the franchise.

Our Take On James Gunn’s Supergirl Comments

Gunn’s comments about Supergirl’s introduction in Superman go to show how invested the DCU is in wanting to explore the Kryptonian heroes, as well as Krypto, as much as possible. While Supergirl may not have been in the Superman post-credits scenes, Alcock’s cameo was still a lot of fun.

What remains to be seen, however, is whether David Corenswet’s Superman will be showing up in Supergirl next year for a cameo. While time will tell, fans can still relive Corenswet’s Superman movie, now playing in theaters.

Source: EW