Comic Title: Action Comics #261
Publisher: DC (National Comics Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: February 1960
On Sale Date: December 31, 1959 Newsstand Date December 31, 1959
Source: House Ad, Superman's Girl Friend Lois Lane #15, Page 21

Copyright Date December 31, 1959
Source: Library of Congress, Periodicals 1960

Frequency: Monthly
Cover Price: $0.10
Page Count: 32
Editor: Mort Weisinger

Title: "Supergirl's Super Pet"
Pages: 8

Feature(s):
Supergirl (of Earth-1)

Writer: Jerry Siegel
Artist: Jim Mooney

Reprinted In:
Action Comics #334 (1966)
Supergirl Archives Vol. 1 HC (2001)
Showcase Presents:Supergirl Vol. 1 TPB (2008)
Supergirl:The Silver Age Omnibus Vol. 1 HC (2016)
Supergirl:The Silver Age Vol. 1 TPB (2017)
Tails of the Super-Pets TPB (2022)

Feature Character(s)

• Supergirl (last appearance in Action Comics #260; next appearance in Action Comics #262)

Supporting Character(s)

• Streaky (origin; next appearance in Action Comics #266)
• Miss Hart (last appearance in Action Comics #254; next appearance in Action Comics #262)

Cameo Appearance(s)

• Superman (several Superman dolls are seen in this story)

Comments:
Supergirl is depicted with a red skirt in this story.

X-kryptonite is created for the first time. It temporarily gives Streaky super powers.

Synopsis:
Supergirl finds a small piece of kryptonite which she takes to a laboratory. She experiments with chemicals in an attempt to find an antidote to kryptonite poisoning. She is unsuccessful and throws the piece into the woods to dispose of it.

Supergirl, as Linda, later befriends a stray cat. The cat is orange with white stripes, she names him Streaky. While playing in the woods, Streaky is exposed to the kryptonite fragment, now X-kryptonite. The radiation gives Streaky super powers. While learning to fly he smashes into a Superman doll and takes the cape.

Streaky flys around town, helping the other cats, and fights a dog. Supergirl hears Streaky and flys to check on him. She sees that Streaky is super now and plays with him. Streaky’s powers vanish suddenly. The effects of the radiation were only temporary, and Supergirl does not know what caused them.