Oswald Loomis was once the buck-toothed and portly host of WGBS TV's "The Uncle Oswald Show", which was later canceled due to bad ratings. Out of spite, he staged a number of weird and threatening pranks throughout the city. Loomis even held Lois Lane hostage--and even tried to marry her. When Morgan Edge intervened, 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.
He currently works as a crime enabler, distracting Superman to allow crooks to commit crimes elsewhere... And to make it very well known to other criminals that "he isn't the kind of fellow to play around with"...
He is also trying to form a partnership with another of Metropolis' fearsome Funsters the Toyman, who doesn't seem as interested in his offer as he was in the Golden Age of Comics.
In the Storyline "Emperor Joker", he plays as Joker City's Only Exorsist, who still acts as childish as ever, but now wields a Halloween Mask made to represent the kid on the cover of "MAD" Magazine... 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 Dimensional Powers of Mister Mxyzptlk.
Prankster has been re-imagined for the New 52, and is now a featured villain in Nightwing. Prankster is now a mysterious masked man. The new Prankster is tall, thin, and has blond hair, and he wears a tailored jacket and custom-designed mask.
It is revealed that Oswald Loomis was young when he witnessed his father, who was the electrical engineer die in an accident. William Cole, Mayor Cole's brother took the fall. However, he blamed both brothers for the death of his father and has sense had a vendetta against them.
Prankster is primarily known for being a cyber-criminal, having broken into several major corporate and government systems. He is fluent in several programming languages, and is adept at cryptography and computer security. The nickname "Prankster" derives from his online handle. He is considered a threat to the city of Chicago, where he resides and operates, as well as to the rest of the world.
Recently, he has begun a series of attacks that extend beyond Internet crimes. His pranks have evolved into complex death traps, and he has kidnapped at least two civilians, including a Chicago alderman.
New Adventures of Superman (Cartoon TV Series 1966 - 1970)
Ruby-Spears Superman (Cartoon TV Series 1988)