Adventure Comics #210 (1955)

Adventure Comics #210 introduces Krypto, also known as The Super-Dog from Krypton. This classic 1955 comic book, written by Otto Binder and illustrated by Curt Swan and Sy Barry, tells the story of Superboy discovering a dog with superpowers just like his own. It turns out that this dog is actually Krypto, Superman's canine companion from his infancy on Krypton.

Jor-El, Superman's father, had used Krypto as a test passenger when experimenting with escape rockets as Krypton was approaching destruction. Although Krypto was supposed to leave before Superboy, his rocket wandered off course and he arrived on Earth when Superboy was already a teenager. On Earth, Krypto quickly acquires powers like flight, super strength, invincibility, and X-ray vision. However, his abilities are weaker than Superman's as they are proportionate to a dog's body.

To maintain a secret identity, Krypto disguises himself as Skip, the Kents' family dog, by dying a patch of his white fur brown. He can turn back to his original appearance by burning off the dye with heat vision.

In summary, Adventure Comics #210 is a classic comic book that introduces Krypto, the Super-Dog from Krypton, with exciting adventures and a fun secret identity twist. This issue was also reprinted in Superboy #165 and DC Special Blue Ribbon Digest #9, making it a cherished addition to any comic book collection.