in Batman: Under the Red Hood John DiMaggio was what fictional supervillain created by Bill Finger
Joker (character) The Joker is a fictional supervillain created by Bill Finger, Bob Kane, and Jerry Robinson who first appeared in the debut issue of the comic book "Batman" (April 25, 1940), published by DC Comics. Credit for the Joker's creation is disputed; Kane and Robinson claimed responsibility for the Joker's design, while acknowledging Finger's writing contribution. Although the Joker was planned to be killed off during his initial appearance, he was spared by editorial intervention, allowing the character to endure as the archenemy of the superhero Batman.
Red Tornado (Ma Hunkel) The Red Tornado is a fictional character, a superheroine in the DC Comics Universe, debuting during the Golden Age of Comic Books. Created by Sheldon Mayer, she first appeared in her civilian identity as Abigail Mathilda "Ma" Hunkel in All-American Publications' "All-American Comics" #3 (June 1939), and became the Red Tornado in "All-American Comics" #20 (Nov. 1940). As the Red Tornado, she was one of the first superhero parodies, as well as one of the first female superheroes (possibly the very first), and, when occasionally disguised as a man, comics' first cross-dressing heroine. (Madame Fatal, earlier that year, was the first cross-dressing hero.)