Descendant
Streaky had a 30th century descendant named "Whizzy" who first appeared in Action Comics #287 (April 1962), and was created by Jerry Siegel and Jim Mooney. A lookalike for Streaky, Whizzy is an orange cat with white lightning-bolt markings on either side of his body.
Supergirl first encounters Whizzy, who also wears a red cape like his ancestor, when she answers a summons from the Legion of Super-Heroes in the 30th century. After defeating the Positive Man, Supergirl is addressed telepathically by a flying cat she assumes is her pet Streaky. She observes, "You have a 'W' insignia on your cape instead of an 'S'! The engraving on your collar explains everything!" True enough, emblazoned on the cat's collar is the following legend: "Whizzy, descendant of famed supercat Streaky."
The effects of the battle with the Positive Man, (defeated by use of a Negative Bird) have caused the Legionnaires to seemingly lose their powers. Supergirl covers for the team, but they betray her. She and Whizzy are tossed into the Phantom Zone.
While in the Zone, Supergirl learns the de-powered Legionnaires are really an invading race of "Chameleon Men". Whizzy assists in the escape from the Zone. The invaders are defeated and the heroes are rescued from their asteroid prison.
Read more about this topic: Streaky The Supercat