|Family||Clark Kent (owner)|
| Powers and|
| Super metacanine strength (temporarily)|
- "He's a good dog, Dad." - Clark Kent, Krypto
Shelby was Clark Kent's Golden Retriever.
Powers and Abilities
Shelby gained temporary powers after being injected with a green kryptonite-steroid serum:
- Super strength: Shelby was able to open the safe door to collect the money.
- Invulnerability: Shelby was strong enough to smash through the window to save Jonathan.
- Enhanced intelligence: This dog had an above average intelligence and was very smart, allowing him to interact with humans easier than what would be possible for normal dogs.
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 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 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.
Shelby is seen in the Kent kitchen after Clark let him in the house to feed him (which he almost forgot to do) before he super sped to work at the Daily Planet.
Shelby is still being fed by (supposedly absent) Clark at the farmhouse but when a suspicious Lois sees the food bowl full she takes the dog to the Talon. Chloe covers for Clark and brings Shelby back. When Clark didn't want to eat the food Lois cooked, he tried to feed it to Shelby who wouldn't eat it.
Season ElevenShelby now lives with Martha in her apartment in Washington, DC.
He is first seen inside Martha's house, barking while watching her going inside Bones' limousine. Later, he seemed very happy to see his former owner, Clark, when he and Lois visited Martha.
Later while Clark and Martha were investigating the man who attacked her and Director Bones, Lois took Shelby for a walk in the neighborhood.
Sometime later, Martha took Shelby for a walk, when suddenly they saw in the sky an enormous storm, created by the god Hades in the center of the Lincoln Memorial and Shelby immediately started barking.
- Season Four: Krypto, Lucy, Spirit, Onyx (deleted scene), Commencement
- Season Five: Arrival, Hidden, Solitude, Lexmas, Fanatic, Lockdown, Fragile, Vessel
- Season Six: Labyrinth, Promise
- Season Seven: Fierce, Veritas
- Season Eight: Instinct
- Season Nine: Metallo, Persuasion
- Season Ten: Abandoned, Finale, Part 2 (flashback only)
- Season Eleven: Olympus
- Smallville Miniseries: Continuity
In the Comics
In the comics, Shelby was the name of one of the dogs Clark Kent grew up with on the Kent farm. One of the names Clark suggests for the dog is "Skipper", in the original Superboy comics Shelby poses as the Kents' pet dog "Skip."
Smallville's version of Shelby has some similarities with the most famous pet of Superman, Krypto, who is also called Super-Dog and appears later in Clark's life.
Krypto was the family dog in Jor-El's household and was used for a test flight of the rocket that eventually carried baby Kal-El to Earth. However, Krypto's rocket was blown off course and drifted in space for many years until the rocket picked up the signal from Kal-El's rocket that landed on Earth. Krypto arrived when Kal-El was a teenager and the two got along famously. Krypto adventured alongside young Kal-El, though he was not publicly known. Krypto had superhuman (or, supercanine) abilities, but with a normal canine intellect.
In the New 52, Krypto appears as a normal dog with no powers and the pet of the El Family on Krypton. His appearance is more alien and he resembles more of a wolf-dog. He was created by Jor-El, who implanted to him some of young Kal-El's DNA in order to create a companion for his son with an unbreakable bond. During the planet's final moments Krypto is sucked into the Phantom Zone while bravely trying to defend the family from the incarcerates, when Jor-El opens a portal, trying to save his wife and son. The baby Kal-El is left in anguish at the loss of his dog.
There is mention of a ghost in the form of a white dog that is protecting Clark Kent and it is later revealed to be Krypto's projection from the Phantom Zone. Superman was later able to pull Krypto from the prison but Krypto was severely injured. Worried, Kal-El carried Krypto into space, and threw him near the Sun, healing Krypto of his injuries.
- Fans of Smallville frequently wondered why Shelby so rarely appeared in scenes set on the Kent Farm. 
- Lois repeatedly refers to Shelby as a female rather than a male, first in Stiletto and then again in Metallo. [As is proper, noting that Shelby is a male]
- While being a dog, Shelby carries similarities to Supergirl's cat Streaky. As gaining super powers, from exposure to Kryptonite.
- Shelby was in a deleted scene in Onyx and seen in one of Clark's trials in Finale, Part 2.
- 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. In Olympus, it is revealed Shelby is currently residing in Washington with his new master, as they live with Martha Kent.