"I regret having tried to destroy Supergirl's powers! She turned the tables on me and I lost my own..."
A Kandorian enemy of Supergirl who is ultimately defeated and rendered powerless by Gold Kryptonite before returning to the bottle city to lead a crime-free life (Act No. 304/2, Sep 1963: "The Maid of Menace!"). Mr. Mxyzptlk once takes on the form of Black Flame in an attempt to humiliate Superman and Batman (WF No. 169, Sep 1967: "The Supergirl-Batgirl Plot!").