A ton of awesome comic book characters have been introduced to us over the years, but not all of these characters were created for the comics. There are a handful of them that were created for other media before they found their way into the comic universes of Marvel and DC. Here is a list of ten comic characters that you may or may not know originated outside of the comics.
[Television] Batman: The Animated Series
That's right folks, everyone's favorite sadistic Joker sidekick wasn't introduced into Batman's Rogues Gallery until Batman: The Animated Series. She was an instant classic! The first comic she appeared in was The Batman Adventures #12 in September of 1993. Over the years she has had her own series and also teamed up with Poison Ivy and Catwoman several times to beat down on Batman. She is my favorite female villain of all time.
[Movie] Iron Man
Agent Coulson was introduced into the Marvel cinematic universe in Iron Man. Before that he didn't exist. He has since become the face of S.H.I.E.L.D., not only in the movies and TV, but in the comic books. His first appearance in the Marvel Comics universe was in the mini-series "Battle Scars."
[Television] Spider-Man and his Amazing Friends
This character was introduced in the classic 1981 animated series Spider-Man and His Amazing Friends. I believe the cartoon reruns on Disney XD. In the show Spider-Man teamed up with a new character named Firestar, a.k.a.Angelica Jones. The character became popular enough for Marvel to bring her into their comic world. She was introduced to the comic universe in 1985's Uncanny X-Men #193. She went on to get her own miniseries and ended up being an original member of the New Warriors.
[Television] X-Men Evolution
X-23 was born from the series X-Men: Evolution and was created by Craig Kyle and Christopher Yost. She has since become one of Marvel's most badass female characters. She is the young female equivalent to Wolverine and quickly became part of the comic books in 2004 in NYX. She was one of several wayward, homeless mutants. She ended up getting her own solo ongoing series, joined the X-Men and X-Force, and is also a big part of the Avengers Arena cast.
[Television] Batman Beyond
Most of the characters on this list have been side/secondary characters or villains. Batman Beyond's Terry McGinnis is a main character in the universe. The incredible Batman Beyond series a followed a teenager who takes on the role of Batman in the not too distant future under the tutelage of an elderly Bruce Wayne. His first appearance in the mainstream comic books was in Batman #700 in June 2010.
Jimmy Olsen, who is a huge part of the Superman mythos, was never a part of the comics until after he first showed up on a 1940s radio show program called The Adventures of Superman. A year after he was on the show he was brought into the DC universe. There was an unnamed "office boy" who made a brief appearance in Action Comic #6, which some people claim was Olsen, but Jimmy's name wasn't actually used in the comics until 1941 in Superman v1 #13.
[Radio] The Green Hornet
I know a lot of people thought that The Green Hornet was a comic book before it was made into a TV show and eventual movie. That is actually true! What many people don't know is that, like Jimmy Olsen, The Green Hornet's introduction came in the form of a radio series on a local Detroit station in January of 1936. The first comic book was published in 1940.
Bebop & Rocksteady
[Television] Teenage Mutant Ninja Turtles
These two knuckleheads didn't make it into the Ninja Turtles comics until after they were introduced as Shredder's henchmen in the classic 1987 cartoon. Their names come from genres of music: bebop is a style of jazz, while rocksteady is a Jamaican music style. They also appeared in in the Archie TMNT Adventures comics.
This adorably quirky character was specifically created for the amazing TV series Smallville. She was basically a high school equivalent of Lois Lane, and fans of the show loved her. She was then introduced in the bi-monthly Smallville comic book series, and in Novemeber 2010 was given an introduction to the official DC comics universe when she appeared outside of the Smallville universe. Her first non-Smallville comic was "Jimmy Olsen's Big Week," which was a serialized Jimmy Olsen story in Action Comics #893.
[Television] Batman: The Animated Series
Another character that was created for the classic '90s Batman series was Detective Renee Montoya. She was assigned to Gotham's Major Crime Unit and partnered up with Harvey Bullock every now and then to fight crime. She was imported into the comic series in 1992, the same year that the animated series debuted. She was also a recurring character in the third season of the animated web-series Gotham Girls. She became a recurring character in the Batman comics after Batman #475.