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 1000 that sold the most issues as well as the one that made the most money in the North American market in April 2018, according to Diamond Comic Distributors; the final tally for April was 449,787 units. In contrast, "The Amazing Spider-Man" #800—another heavily promoted milestone issue released in the following month of May—sold 411,480 copies to retailers. "Action Comics" #1000 also charted in May, as the 23rd most-ordered comic with another 52,129 units sold. Action Comics 1000 "Action Comics" #1000 (cover dated Early June 2018) is the thousandth issue of the original run of the comic book/magazine series "Action Comics".