In Roman mythology, the messenger of the gods.
In January-February 1944, after an accidental explosion in the city of Rome has awakened Mercury from his centuries-long sleep beneath the ruins of "what once was a temple dedicated to pagan rites," Mercury flies to America, where, more in pursuit of mischief than anything else, he leaves a trail of pandemonium in his wake—and aids the cause of the Metropolis underworld—by committing a series of mayhem-inducing pranks, as when he puts the city's police dispatchers to sleep with his magic staff and then sends all of Metropolis's police officers to chasing one another about the city by putting out a bogus radio call to the effect that bandits disguised as police officers are committing crimes using automobiles disguised as police cars. Superman ultimately apprehends the mischievous Mercury, however, and agrees to conceal his true identity from the population at large—thus sparing the winged god from the public humiliation of having been defeated by a mere mortal—in return for Mercury's promise to undo the trouble he has caused and to apprehend the criminals who have been aided by his antics (S No. 26/4: "The Quicksilver Kid!").