Who's Krypto?

Who's This? A super dog.

The facts: Krypto first appeared in Adventure Comics #210 (March 1955), not as Superman's dog, but as Superboy's, in a story by Otto Binder, Curt Swan and Syd Barry. Originally meant as a one-off, he was a hit and became a member of the Boy of Steel's cast. Over the years, he'd become a founding member of the Legion of Super-Pets, would get his own solo strips in Superman Family, and appear alongside Superman's adult supporting cast. When the Superman books were rebooted by John Byrne, there was no Superboy era, so he relegated Krypto to a pocket universe where a Superboy grew up and inspired the Legion of Super-Heroes (that version is turned into an ordinary dog by story's end). An Earth dog called Krypto was adopted by Bibbo and then the Kon-El Superboy in the 90s, but eventually, the Superman creative teams couldn't resist reintroducing Superman's Kryptonian pet, one that follows Superman back from Brainiac's false Krypton in the early 2000s. After Infinite Crisis, Superman: Birthright makes Krypto once again the actual dog of the El family who survived Krypton's destruction. He's been around ever since, even in the New52 (where he's a big husky), palling around with Superman, Supergirl, and other members of the Superfamily. He's also appeared in all-ages comics like DC League of Super-Pets and Superman Family Adventures.
How you could have heard of him: Forgetting the fact that this very blog covered every appearance by Krypto up to the beginning of the New52, Krypto has enjoyed a lot of visibility across media in the past few years. In the comics, he's had his own mini-series and currently features in the Supergirl series. On television, he appeared in Superman & Lois and My Adventures with Superman (though neither is super). And most prominently, he became a meme-able media darling thanks to 2025's Superman film, reappearing in Supergirl a year later. He was also one of the stars of the DC League of Super-Pets animated movie in 2022, voiced by Dwayne Johnson. And this is only the most prominent fraction of his alt-media appearances. I dare say Krypto is a household name.
Example story: Dog Days of Summer #1 (July 2019) "The Crucible" by Collin Kelly, Jackson Lanzing and Cully Hamner

As I mentioned, I covered every Krypto appearance from 1955 to the early 2010s, so here, I had to pick something more recent. In this short tale, Krypto and his human investigate the Crucible of the Benevolent Cosmos, a spaceship that's counting down to SOMEthing. Ominous. Superman WOULD have brought somebody else - like Wonder Woman - but none were available. Krypto is a good, obedient boy Supes can trust (unlike in the movies). The ship has "levels" (tests?), including one that's simply trying to kill the Kryptonians with simulacra of their old foes (did Zod ALSO have pets or does Krypto have his own rogues' gallery?).

Superman really SHOULD work with Krypto more, according to these captions. Maybe it's the slobber he doesn't like.

They finally make it to the center of the ship - a "kryptonite sun" - with a single means of escape, a door for one. Of course, Superman tells his dog to use it. Use it and go protect Lois. And a good boy always does what his master tells him, right? Well, dogs are still dogs, and...

Neither of these characters were ever seen again... No, wait! It seems like they passed the test! The reason the ship had two portals in and one portal out was to see if Earth's champions would have a bond worthy of saving their planet for.

And if you're one of those cynical heathens who think super-pets are silly and shouldn't be in your comics, the last splash has a message for you:

I may be a cat person - you didn't give Streaky his own entry, you cowards! - but Krypto is the best boy.

Who's Next? A dead planet.