Oswald Loomis, alias the Prankster was once the popular host of the "Uncle Oswald Show," a WGBS-TV early morning children's program, Oswald Loomis unleashed a host of dangerous pranks upon Metropolis when ratings and cancelation cut short his comedic career. Dubbing himself the Prankster he set about playing dangerous practical jokes targeted at Metropolis and its citizens.
Loomis even held Lois Lane hostage and even tried to marry her. When Morgan Edge, he was hurled out of a trap door 30 stories high. Superman managed to save Morgan Edge and freed Lois Lane before Loomis surrendered. The prankster then escaped his guard for fear of prison.
Oswald Loomis later returns a younger, more athletic body after selling his sole to Lord Satanus. His personality has also changed he no longer a joke, he is now a manic trickster with the a twisted desire to make the world laugh. When Metropolis was upgraded by Brainiac 13. Oswald Loomis takes advantage of the futuristic technology, creating high gadgets and weapons, which retain a comical theme. Oswald Loomis challenges Superman again as he was suffering from Kryptonite poisoning during the battle, and is hospitalized in S.T.A.R. Labs shortly thereafter.
When the Joker took over the earth he was Joker City's only exorcist, who still acts as childish as ever, but now wears a Halloween mask. Who's goal is to expel the evil from those who still believe in science, John Henry Irons in particular which the Joker has practically destroyed while wielding the 5th Dimension powers of Mister Mxyzptlk.
He is one of the various super criminal sent to to the penal colony on the planet Cygnus 4019, which has been nicknamed Salvation.
The Prankster was among the many of criminals who was caught and placed in the Phantom Zone by the people of Kandor. Superman freed Prankster to be taken to Belle Reve.