Kobra is the reptilian-garbed villain who uses his vast arsenal of alien weapons to wreak havoc all over the Earth with the intent of benefiting from the resulting chaos.
A Siamese-twin, Kobra shares a psychic bond with his brother, Jason Burr. Separated shortly after birth, the twins are sworn opponents, Jason having sided with law and order and his sibling having been raised in the ways of evil by a cobra cult (Kobra No. 1, Feb/Mar 1976: "Fangs of the Kobra!").
As Batman tells Superman, "Kobra is one of the deadliest men alive! I've seen his operations--and I tell you, this guy is practically the Devil himself! He can destroy entire continents...raise the dead...and I don't know what else!" According to Aquaman, Kobra is "more slippery than a hundred eels!" (S No. 327, Sep 1978: "The Sandstorm That Swallowed Metropolis!").
Superman first encounters Kobra after the masked criminal breaks into the apartment of Clark Kent to retrieve a teleportation device confiscated from the Atomic Skull. Surprising a groggy Kent, Kobra learns of Kent's dual identity of Superman (S No. 326, Aug 1978: "A Million Dollars a Minute!").
Subsequently, Kobra and his gang cover Metropolis with sand and force Superman to vacuum it up in order to filter out a deadly nerve toxin that has been spread over the city causing the Man of Steel to muse, "you delight in creating disasters--which you then profit from!" Superman agrees to help Kobra after the villain kidnaps Jonathan and Martha Kent from the past and threatens to kill them, potentially altering the "personal history" of Superman. Through a series of subterfuges, Superman is able to rescue his imprisoned parents while destroying Kobra's filtration device. Frustrated, Kobra escapes in his giant invisible ark, presumably to plan another incredibly complex crime (S No. 327, Sep 1978: "The Sandstorm that Swallowed Metropolis!").