Some characters have been known to 'break the fourth wall' by speaking to, or about, the audience. Not only do they talk to the reader, but they (usually) know that they are fictional creations in a story. On occasion, this may be a vehicle for dramatic irony. Deadpool, the most well known example of this phenomenon, has been known to refer to his own history in issue format, lean on the panel borders, and see or touch his thought boxes and word balloons.
The fourth wall can also be reinforced by a character saying that, i.e., 'this isn't a movie, you know'.
Here are some characters that have broken the Fourth Wall:
(Note: Characters may have broken the 4th wall at one point in time, but that doesn't necessarily mean that they currently retain the knowledge of the world beyond the comic they are in.)
Note: This list does not include creators who are in (auto)biographical comics as these stories are about the creators and set in the real world, not in a fictional one. Also, homages to creators or "easter egg" appearances do not count, the characters have to explicitly make clear they are breaking the fourth wall.
Some writers break the fourth wall by inserting themselves into the story, wherein their character admits to writing the story they are appearing in:
- Alan Moore as Alan Moore: Wrote himself into Promethea when "the world was ending" and our realities were converging, he is seen writing the script for the page he appears on.
- Ben Templesmith as Ben Templesmith: He claims to be the biographer for Wormwood, Wormwood writes him off as some loon but Templesmith gets irate claiming he's had Eisner nominations three years in a row now, yeah, whatever.
- Brian K. Vaughan as Brian K. Vaughan: Written into Ex Machina as the writer of the comic that will follow the life of Mayor Hundred, shares some of his own personal stories and feelings about New York City and 9/11. Y: The Last Man is also referenced where he clears up that the Daughters of the Amazon are asexual not lesbians. Ironically, he criticizes the use of inserting oneself into the story, mentioning Grant Morrison and saying that it's too "meta" and takes him out of the story.
- Grant Morrison as The Writer: Perhaps the most well-known example, Grant Morrison inserted himself into the end of his Animal Man run (which was already full of instances where the Fourth Wall was broken) and he explains everything to Animal Man, why he killed his family, what his views are, etc. He mentions that he's also writing Doom Patrol and in the end "restores" everything to the status quo.
- J.H. Williams III as J.H. Williams III: Written into Promethea, alongside Alan Moore (see above); is seen drawing the two-page spread he appears in.
- Jonathan Ames as Jonathan A.: Protagonist of The Alcoholic. Although this is something of a unique situation, being that the comic is semi-autobiographical, the comic is not meant to be taken as a factual detailing of the writer's life and has fiction inserted, however, the character does talk directly to the reader at points. Although he is more of a character then a creator writing himself into a comic, he is placed in this list due to the fact that his name and life are based on his creator.
- Roy Thomas and his wife Jeanie are introduced at a Halloween Party to the other guests in The Avengers #83, written by Thomas. They are dressed as Spider-Man and Mrs. Fantastic. Jeanie Thomas is asking one of the Avengers which of them Mrs. Peel is.
- Peter Milligan as Miles Laimling: "Laimling" being an anagram of "Milligan". He is originally just some guy writing "The Great American Novel" in Hotel Shade and stealing the identities of Shade, Lenny and Kathy as he writes them. Eventually he breaks the Fourth Wall entirely when he says he's going to write their adventures as a comic and looks at the reader.
- Tony Harris as Tony Harris: Appeared with Brian K. Vaughan (see above), he is portrayed as the "cooler" of the two and brings his art portfolio to show off to Mayor Hundred's staff. While Vaughan talks with Hundred, Harris hangs out with January and other staff and draws Bradbury in a "badass-style" pose.
Other creators have also appeared in comics, although were inserted by someone else, rather then doing it themselves:
When characters break the "Fifth Wall," it shows they have knowledge of other fictional characters from another, unrelated actuality.
in The Amazing Spider-Man #123, after being hit through a window by Spider-Man, Luke Cage says "I dig, Spider-Man ... but here's something you don't! Some dudes have to do this number for a livin' -- we ain't all rich playboys like Bruce Wayne." Note that Luke Cage should probably not know of Bruce Wayne, and vice versa.
In Superman #50, Mr. Mxyzptlk makes several statements hinting that he is also the Impossible Man from Marvel Comics and has knowledge of the Fantastic Four, such as "Having fun with my new fantastic friends," "back to my four new friends," It's blubbering time," and "Sometimes it's just impossible to remember what I look like from world to world."
Some comics have recap pages before the actual story in which characters from that issue (or sometimes the previous one) show up and talk to the reader, breaking the Fourth Wall. These instances are generally isolated and after the recap page, the characters no longer have the ability to break the Fourth Wall. For examples of this, check out the Cable/Deadpool and Irredeemable Antman series.
Likewise in pages outside of the story, usually at the back of the comic in distinctly separate areas, characters will often address the reader for promotional purposes or for humorous effect.