Krypto the Superdog is the canine best friend to Superman and his alter ego Clark Kent. He appears as an average medium sized dog who transforms into his hero persona by donning a gold collar with Superman’s symbol on the tag and a cape similar to the one worn by the Man of Steel. Created by Otto Binder and Curt Swan, Krypto was introduced 70 years ago in Adventure Comics #210 (March 1955).

Since the people of Krypton share similarities with those of Earth, it stands to reason that animals would be the same. Enter Krypto, the precocious young dog who was the faithful pet of toddler Kal-El. When Jor-El was testing prototypes for the rocket that would transport Kal-El to Earth, he decided to use Krypto as the test subject. Though the rocket launched successfully, meteors struck the capsule, knocking the ship off course. It still made it to Earth, however, Krypto arrived years later than expected when Kal-El was already a teenager.

Like his master, the yellow sun affects Krypto giving him superpowers. They are proportionate to Superman’s, similar to the strength and sense differences between humans and dogs. For instance, he has superstrength for his size, which is less than Superman’s power, but he has super-hearing and sense of smell that are better than Superman’s, like that of a normal dog versus a normal human. His intelligence level is also higher than that of regular dogs, more on par with average humans, which helps him when working together with Kal-El.

When not fighting crime or saving the day, Krypto spends his time posing as the Kent family dog, Skip. To protect his identity, the Kent’s cover his fur in brown dye, then when he goes out to help Superman, he uses his heat vision to burn the dye from his fur.

Since Crisis on Infinite Earths there have been multiple versions of Krypto. The first was in a pocket universe where he battled Phantom Zone criminals and gave his power to Superboy. The next one was a normal Earth dog with no superpowers, who still helped Superboy when he could. Eventually Krypto was joined by Grokk the Living Gargoyle, and other special creatures to fight Agenda’s influence over Cadmus.

The third version of Krypto, who was introduced in the early 2000s, had the same super-abilities of the pre-Crisis version but he had the intelligence of a regular dog. The disparity between his powers and intellect caused problems. He could do serious harm to villains by biting them too hard or cause property damage at home just because he wanted to go outside. To deal with the issue, Superman took Krypto to the Fortress of Solitude where he and his robots trained the pooch.

In Superman/Batman, Krypto joined Superboy and others on a mission to save Batman and Superman from the clutches of President Lex Luthor by fighting Secret Service agents so they could be freed. Krypto went to live with Superboy in Smallville where he protected Conner from Superboy-Prime and was injured in the process. When Conner died, Krypto ran away for a time, returning when Jimmy Olsen was in danger and needed saving.

He fought Superboy-Prime once again, giving the heroes time to join the battle against the Sinestro Corps, and he helped Superman defeat Atlas. After Jonathan Kent died, Krypto went back to the Kent farm to comfort Martha and be her protector. During The New 52, Krypto had been pulled into the Phantom Zone while protecting baby Kal-El on Krypton. Superman found him years later when he was pulled into the Phantom Zone himself and brought Krypto back to Earth.

Not only did Krypto work alongside Superman and Superboy, he was also a part of teams like the Legion of Super-Pets, who made their first official appearance as a team in Adventure Comics #293 (March 1962). Krypto is joined on the team by Streaky the Supercat, Beppo the Super-Monkey, Comet the Super-Horse, and the alien Proty II. The rag-tag team was formed following an alien invasion by the Brain-Globes. After they manage to summon the Legion of Super-Heroes from the future and control them, the world is in desperate need of a hero. 

Upon discovering that the Brain-Globes cannot control animals, Krypto, Streaky, Beppo and Comet gather together to battle the alien forces. The pets manage to defeat the aliens decided to officially form the animal branch of the super club, the Legion of Super-Pets. Proty II would later join the team. Super Sons Annual #1 later introduced a new assembly of super-powered pets. Based in the post-New 52 and DC Rebirth universe, this team consisted of Krypto, Damian Wayne’s dog Titus, Streaky, Flexi the Plastic Bird, Bat-Cow, and Clay Critter. 

The team was briefly disbanded following a battle with Dex-Starr and Harley Quinn’s hyenas Bud and Lou. However, when a group of dogs were kidnapped by an alien thief, Krypto and Titus reformed the group to rescue them. Outside of comics, a version of the Super-Pets was adapted into an animated cartoon series. This series featured Krypto, Ace the Bat-Hound, Beppo, B’dg, Comet, Gleek, Jumpa, Streaky, Storm, and Whatzit.