Drang

In August 1963, exposure to Red Kryptonite temporarily transforms Superman into a fearsome Kryptonian “Drang,” a colossal flying snake, purple in color, with a head like a dinosaur and a single white horn protruding from its forehead. Unaware that the hideous monster is actually Superman, but fully aware that it is Kryptonian and therefore vulnerable to Kryptonite, the U.S. Armed Forces are on the verge of destroying it with kryptonite bullets when finally, with some crucial assistance from Supergirl, Superman succeeds in alerting his attackers to his true identity and in getting them to hold their fire. Soon afterward, the effects of the red kryptonite fade and vanish, and Superman is restored to his normal form (Act No. 303: “The Monster from Krypton!”).