Streaky
From superman.nu: Supermanica
Streaky the Super-Cat
The mischievous feline pet of Linda Lee Danvers, a.k.a. Supergirl, Streaky has on-again, off-again super-powers due to exposure to X-Kryptonite, a failed Kryptonite antidote attempt by Supergirl (Act No. 261, Feb 1960: "Supergirl's Super-Pet"; and others).
An ordinary-looking orange cat with white lightning-bolt markings on either side of his body, Streaky is a member of the Legion of Super-Pets.
His 30th Century descendant is named Whizzy.