Before he was adopted by the Kents, he belonged to Zack and Josh Greenfield, who work at a veterinary clinic in Smallville. They called him Einstein, because they had enhanced the dog's intelligence and strength with kryptonite. Shelby ran away from them, and was hit by Lois Lane. She brought him to the Kent farm, where Clark Kent discovered the dog's super strength. At first, Clark wanted to call him Skippy, but later thought of naming him "Krypto", because his origin was cryptic. When Jonathan Kent agreed to keep the dog, Clark and Martha named him "Shelby", after a dog that Martha once had as a child. Despite the fact that the dog was a male, Clark, in particular, felt Shelby was a better name than what Lois had in mind: "Clarky" (on the grounds that he was totally annoying and she couldn't come within ten feet of him without feeling ill).

Shelby no longer has enhanced abilities because the serum that was used wore off after a few days. He remains a fond member of the group at the Kent farm, with even Lois being fond of Shelby in her own way, despite her being allergic to him.

When Dr. Hudson inhabited Clark's mind, Shelby's barking at Martian Manhunter helped Clark come out of the prolonged hallucination.


  • Super metacanine strength (temporarily)
  • Invulnerability (temporarily)
  • Enhanced intelligence
  • Shelby was played by a Dog named Bud.
  • Shelby hasn't appeared since Lois and Clark moved into their new apartment. Al Septien revealed there was a scene cut where Clark placed him in the care of Conner Kent, knowing they both need companionship. This was supposed to be a nod to Clark doing the same to Krypto in the comics.
  • Lois repeatedly refers to Shelby as a female rather than a male, first in Stiletto and then again in Metallo.
  • Fans of Smallville frequently wonder why Shelby so rarely appears in scenes set on the Kent Farm. Shelby only appeared in 21 episodes between his first appearance in the Episode "Krypto" and the Smallville series finale. His series finale appearance was only via flashbacks.