Spot
From superman.nu: Supermanica
The robot dog created by Jor-El as a replacement pet for the baby Kal-El after Krypto is accidentally sent into space.
Exiled to the Phantom Zone by criminals, Spot is released by Superboy in December 1964 as a playmate for Krypto --whom he saves when he collides with a Kryptonite meteor, destroying his mechanical body in one final heroic act (SB No. 117/2: "Krypto's Superdog Pal").