Action Comics swap bodies with a gorilla and his strip was renamed Congorilla. The introduction of Supergirl by Otto Binder and Al Plastino occurred in issue #252 (May 1959). Following this debut appearance, Supergirl adopted the secret identity of an orphan "Linda Lee" and made Midvale Orphanage her base of operations. In "Action Comics" #261 (February 1960), her pet cat Streaky was introduced by Jerry Siegel and Jim Mooney. Supergirl joined the Legion of Super-Heroes in issue #276 and acted for three years as Superman's "secret weapon," until her existence was revealed in "Action Comics" #285 (January 1962). In the view of
Action Comics 1 copy for US$1.5 million, making it the most expensive and most valuable comic book of all time. The copy sold is the third highest-graded copy from the CGC, which stands at 8.5 VF+ grade. As of 2011, there were six known Comic Guaranty LLC (CGC)-graded copies with a grade above VG (CGC 4.0), with only one issue having the grade of VF/NM (CGC 9.0) at that time. EC and "Mad" publisher William Gaines, whose father was also a comic book publisher and had business dealings with DC Comics at the time "Action Comics" #1 was published, claimed in a "Comics