Jack-A-Dandy is a fictional comic book

Comic book

A comic book or comicbook is a magazine made up of comics, narrative artwork in the form of separate panels that represent individual scenes, often accompanied by dialog as well as including...

 super villain created by writer Alan Moore

Alan Moore

Alan Oswald Moore is an English writer primarily known for his work in comic books, a medium where he has produced a number of critically acclaimed and popular series, including Watchmen, V for Vendetta, and From Hell...

 and artist Rob Liefeld

Rob Liefeld

Rob Liefeld is an American comic book writer, illustrator, and publisher. A prominent artist in the 1990s, he has since become a controversial figure in the medium....

, as guided by Mort Weisinger

Mort Weisinger

Mortimer Weisinger was an American magazine and comic book editor best known for editing DC Comics' Superman during the mid-1950s to 1960s, in the Silver Age of comic books...

. The character is modeled after the Joker

Joker (comics)

The Joker is a fictional character, a comic book supervillain published by DC Comics. He is the archenemy of Batman, having been directly responsible for numerous tragedies in Batman's life, including the paralysis of Barbara Gordon and the death of Jason Todd, the second Robin...

 and the Riddler

Riddler

The Riddler is a fictional character, a comic book character and supervillain published by DC Comics, and an enemy of Batman. Created by Bill Finger and Dick Sprang, the character first appeared in Detective Comics #140 ....

 to be the archenemy

Archenemy

An archenemy, archfoe, archvillain or archnemesis is the principal enemy of a character in a work of fiction, often described as the hero's worst enemy .- Etymology :The word archenemy or arch-enemy originated...

 of comic book hero Professor Night

Professor Night

Professor Night is a fictional character created by Alan Moore in the Supreme comic book, wherein most heroes and villains are thinly disguised counterparts of DC icons. Although his name is derivative of Doctor Mid-Nite, the character is otherwise clearly intended be a counterpart of Batman...

, which is a character based on the Batman

Batman

Batman is a fictional character created by the artist Bob Kane and writer Bill Finger. A comic book superhero, Batman first appeared in Detective Comics #27 , and since then has appeared primarily in publications by DC Comics...

 mythos.

His gimmick consists of dressing like an early twentieth century high society gentleman and creating havoc out of boredom. In one of the Supreme

Supreme (comics)

Supreme is a fictional superhero created by Rob Liefeld and first published by Image Comics, then Maximum Press, and later by Awesome Entertainment...

earlier stories, he teams up with Darius Dax to switch Supreme and Professor Night's minds, but the duo manage to reverse the effect and switch the minds of the two villains.