It is said that dog is man's best friend, and even Superman had a little bit of canine companionship.
Krypto is not an ordinary pet. When Jor-El (Superman's father) became reasonably convinced that Krypton's days were numbered, he was determined to save his son. His plan was to send his toddler, Kal-El, to Earth in a small space pod.
When he was ready to test a prototype of the craft, Krypto was put inside, since he was close in size and weight to the young boy.
Unfortunately, the dog's flight was knocked off course, and Krypto drifted through space for years. By the time he finally landed on Earth, Kal-El was now a teenaged boy!
The 1955 comic book debut of the Superboy - Krypto team is shown here:
As you can see, the yellow sun and gravity change gave Krypto special powers, too.
Just as Superman has an alter-ego, Krypto does as well. At home with the Kent family, he is "Skip" and he adds a brown spot to his fur.
Krypto was also a member of The Legion of Superpets and The Space Canine Patrol Agents.
What makes Krypto extra special, is that he gave his life for Superman. To save his master, Krypto lunged at the throat of Kryptonite man, killing him. But the exposure was too much for him to take, and he died from the exposure.
Of course, in the comic world, there are always do-overs, and Krypto has had a few reincarnations.
The picture below is Krypto the Superdog, from the 2005 television series of the same name.
In the series, Krypto lives in a suburb of Metropolis with a young boy. He speaks in clear English, and he teams up with other animals, Like Streaky the cat and BatDog to fight crime. It's not exactly Krypto the way I remembered him - but it was a cute series.