Ever since her earliest appearances on "Batman: The Animated Series," Harley Quinn has been very predictable in one sense -- you can't possibly predict what she is going to do next! Her all-over-the-place attitude carried over to the comics books when she became part of the DC Universe in 1999. In the years since, she has been a star of three ongoing series plus a featured character in both "Gotham City Sirens" and then three volumes (and counting) of "Suicide Squad." This is on top of more one-shots and miniseries than any DC characters outside of Batman.

RELATED: The 16 Worst Things The Joker Has Ever Done

Harley's unpredictability has served to make her a superstar, but it also leads to a number of crazy moments over the years. We've collected 15 shining examples where Harley Quinn has entertained us as a comic book character within the main DC continuity.

15 HARLEY INITIATES JOKER'S DAUGHTER

When "New Suicide Squad" launched following the conclusion of the first "New 52" "Suicide Squad" series, incoming writer Sean Ryan took an interesting tact with the roster. He added two characters -- Deathstroke and Joker's Daughter -- that were seen as essentially replacements for current team members, Deadshot and Harley Quinn. Naturally, Harley did not like being on the same team as a woman calling herself Joker's Daughter, who literally was wearing Joker's face on her own.

However, this being comics, you're meant to expect a certain degree of conflict in a series, so it seemed like this would be the status quo for a while. But then? Nope! In "New Suicide Squad" #3 (by Sean Ryan, Tom Derenick, Jeremy Roberts and Rob Hunter), Harley Quinn abruptly beats her up, kicks her into traffic and that's it for Joker's Daughter in the series (she does survive, though). What a cool, out of nowhere plot resolution!

14 HARLEY SOLO

In Harley's first "New 52" series, she initially had a job as a psychiatrist at a nursing home. This led to a crazy situation in "Harley Quinn" #4 (by Amanda Conner, Jimmy Palmiotti and Stephane Roux) where she essentially kidnaps a suburban family because one of her patients told her how her family has ignored her. As it turned out, the patient was just dealing with Alzheimer's and the family was very active in her life.

That "shoot first and ask questions later" approach also came to play in an amazing scene in the issue that is a riff on the scene between Han Solo and Greedo in "Star Wars." Harley has a price on her head and Guido is there to collect on it. It is very amusingly meta to see Harley sort of go along with the script and, of course, get her "Han shoots first!" moment. Of course, instead of a blaster, it's a fork to the chest!

13 HARLEY, BATMAN AND BRUCE WAYNE!?

In "Harley Quinn: Valentine's Day Special" #1 (by Jimmy Palmiotti, Amanda Conner and John Timms), Harley Quinn sees that Bruce Wayne is involved in a charity auction and becomes determined to "win" him. She first needs to get the money to do so. Working with a small-time crook, she manages to steal a million from a Bernie Madoff-esque guy. She then manages to win the auction, only for Bruce to then get kidnapped!

There's some awesome dream sequences for both Harley and Bruce as they imagine their lives if they did end up with each other. Bruce manages to convince his kidnapper that he will help him out (the bad guy has some legitimately good ideas for sea life but kept getting turned down for research grants due to companies putting the squeeze on the people handing out grants), but not before Harley bursts in to rescue him. They then have a legitimate date and actually get along quite well. Harley even gets a goodbye kiss. She is then visited by Batman and she ends up sharing a kiss with him, as well! So yes, Harley got to make out with both Bruce Wayne and Batman in the same comic!

12 HARLEY SAYS GOODBYE TO THE JOKER

This is a tricky one, since a very similar scene to this took place in "Suicide Squad" #15. This one had a bit more gravitas to it, though, so we're still including it on the countdown. It seems like Harley has a lot of these "I'm finally done with the Joker" moments, but the one in "Harley Quinn" #25 did seem a bit more believable than most others. Harley breaks into the Joker's cell and they have a confrontation with each other where the Joker attempts to re-assert his dominance in their relationship... but Harley is not having it.

They share a kiss, but Harley then bites a chunk of his lip off. She tells him he disgusts here and that she is through with him. She goes a step further to once again put a gun to his head (as she has in the past, as you'll see later on), but this time she remarks, “I finally get why Batman never just killed you all these years. It would give you exactly whatcha want.” While we've seen Harley break things off before, this is one of the few times when she's managed to truly look down upon the Joker, which made it work well.

11 TRUTH OR DARE WITH JIMMY OLSEN AND BIZARRO

In "Harley Quinn: Road Trip Special" #1 (by Jimmy Palmiotti, Amanda Conner and Bret Blevins), Harley's uncle dies, so she goes on a road trip across country to visit her family, and she brings Poison Ivy and Catwoman along for the ride. They make a number of stops along the way and have some misadventures, but they also do some amusingly normal tourist things, like stop off at roadside attractions and the like.

The highlight of the trip, though, has to be when they pick up a hitchhiking Jimmy Olsen and Bizarro (as a tie-in to the "Bizarro" series that was going on at the time). Harley had been trying to get Selina and Ivy to play "Truth or Dare" with her for a long time, but now with her new guests, she finally has someone to play with. And playing "Truth or Dare" with Bizarro is as hilarious and bizarre as you would expect. A mooning Bizarro is... well, it's definitely something to see.

10 HARLEY'S INNER JOKER

The "Harley Quinn/Power Girl" mini-series was a delightful example in just upping the crazy ante over and over again until it got to some utterly bizarre cosmic plot points, perhaps the nuttiest of which was when they came across the Harvester of Sorrows in "Harley Quinn/Power Girl" #5 (by Jimmy Palmiotti, Amanda Conner, Justin Gray, Stephane Roux and Flaviano). The Harvester of Sorrows is sort of a riff on Galactus, only here, when he devours Harley, she ends up being too much too handle for him.

The reason she affects him so much is because of something that Palmiotti and Conner often do not touch on in their "Harley" comics, as they tend to play up the "zany" angle. Harley is a highly disturbed person, and her psychosis comes out in the form of her "Inner Joker," which ends up overloading and basically taking control of the Harvester of Sorrows in a really trippy visual.

9 NOT QUITE DEADPOOL

Introduced at the end of her previous series, a hilarious new addition to Harley Quinn's cast of characters is her former stalker, Wayne Wilkins, who took on the costumed identity of Red Tool. In the Post-Rebirth series, "Harley Quinn" #1 (by Amanda Conner, Jimmy Palmiotti and Chad Hardin), we see Harley team-up with Red Tool to take on a sudden outbreak of zombies. Basically, this was a way to combine Harley with the two biggest pop culture phenomena in comics -- Deadpool (Red Tool) and zombies!

However, while Red Tool is a lot like Deadpool, he's not totally like him. Case in point, he doesn't have a healing factor, so after he is bitten by a zombie and Harley cuts his hand off, it stays cut off. She then hilariously gets him to the hospital by sending him in a catapult!! The way Red Tool has been treated in the current series is a total blast, quite literally.

8 HARLEY GIVES ADVICE

In an awesome series of issues in Harley's original ongoing series, Karl Kesel returned to his original writing stomping grounds (Kesel wrote "Adventures of Superman" for a few years) by having Harley Quinn and Poison Ivy move to Metropolis in "Harley Quinn" #14 (by Kesel and artists Terry and Rachel Dodson). They commit crimes while they are there, of course, but to keep herself amused, Harley takes on the role of Holly Chance, Advice Columnist (with some Ivy-assistance in brainwashing Perry White into giving her the gig).

Holly's advice is often salacious, sometimes ridiculous, but always hilarious. It is especially fun to see her befriend Jimmy Olsen while she is at the Daily Planet, as she had vowed to kill him earlier in the series. Luckily (for him), he doesn't recognize Holly as Harley, so he has no idea that he is very close to danger as he tries to hit on the new columnist.

7 HARLEY'S INFINITY WAR

In "Harley Quinn" #12 (by Jimmy Palmiotti, Amanda Conner and John Timms), Harley Quinn teams up with Power Girl and they find themselves transported into outer space while fighting against the Clock King and the Sportsmaster. They learn that the only way that they will be able to get themselves home is through a powerful Infinity Ring. The Infinity Rings, however, have been collected by the mighty Manos, who ultimately wants to use them to destroy all life in the universe. In case you missed it, this is a very thinly-veiled Thanos / Infinity Gauntlet reference.

They go to Manos for help (he hangs out on a bunch of floating rocks in outer space), but when they learn how evil he is, Power Girl wants to fight him. Manos is about to destroy them when, well, Harley just steals the Infinity Rings right off his hands and then accidentally kills him with them. In her defence, she didn't know that they were loaded.

6 HARLEY VS. ISIS

In "New Suicide Squad" #12 (by Sean Ryan and Philippe Briones), the Squad deals with a splinter group of the League of Assassins that decided they didn't need to hide anymore. So, they began to take over large parts of the Middle East, as this was basically Ryan's attempt at doing a superhero version of ISIS. Since the group was recruiting new members like crazy, the Squad sent Deadshot, Captain Boomerang and Black Manta in to go undercover, with Harley Quinn, Parasite and Reverse Flash serving as their rescue squad.

Things take a turn when the rescue squad is captured and Black Manta seems to be actually converted to the League's cause. In one of the darkest moments in the storyline, Harley finds herself captured with a bunch of little kids who have been kidnapped from their families to be made into child soldiers. Harley feels a real affection for the kids, and she befriends them all. However, when she rescues them, she uses so much disturbing violence that she inadvertently completes the indoctrination of the kids. Very bleak stuff from Ryan.

5 I CAN'T BELIEVE IT'S NOT RACIST!

Egg-Fu was one of the strangest characters in the DC Universe, and not just because he was a giant talking egg. No, he was strange because he had an awesome concept (he was a giant talking egg!) that was sadly mixed in with a super-duper racist depiction of an Asian man. Like, super racist. So that was the strange thing; on the one hand, you had a great idea for a character, but on the other, he was way too racist to use.

The writers of "52" managed to redeem him pretty well by introducing him as Dr. Chang Tzu, but "Harley Quinn Annual" #1 (by Amanda Conner, Jimmy Palmiotti and John Timms) went one step further by introducing the "New 52" version of Egg-Fu, as Edgar Yeung, an egg-man who just wanted people to like him. The issue was a scratch-and-sniff comic book, which just adds to the "WTF?"-ness of it all. Edgar even cried yolks! He ended up becoming a regular supporting cast member of "Harley Quinn" after this, which is about as shocking as anything.

4 KICKED OUT OF HELL

"Harley Quinn" #20-22 (by Karl Kesel, Brandon Badeaux and Dan Davis) see Harley Quinn end up in Hell after dying in "Harley Quinn" #19. At first, she is forced to deal with being stuck in a shootout between the cops and all of her former henchmen that died over the years, but then she manages to sort of break out of her assigned punishment.

Since she is now loose in Hell, she is being hunted by Ulysses Highwater, Hell's own bounty hunter. However, Harley figured out that Highwater was obsessed with finding someone else in Hell much more than Harley. He wanted to find the man who, back in his time (the 19th Century) had "corrupted" his son. As it turned out, both his son and this man were still together, but not in Hell. When Harley successfully messes with him and his backwards beliefs, she ultimately causes so much chaos that she ended up getting banned... from Hell! Yes, she was the first person too annoying to stay dead! So, she got sent back to Earth and the living.

3 GIVE GOOD FACE

Deadshot-Joker-Face

In the "Hunt for Harley Quinn" that ran in "Suicide Squad" #6-7, Harley Quinn learned of the Joker's alleged death and decided that she had to break out from the Suicide Squad to deal with the news. Along the way, as her teammates hunt her down, we see her "New 52" origin. At the end of "Suicide Squad" #6, Harley is arrested by the Gotham City Police, but we know that is because she is trying to get to the only piece of Joker left, his face. At the time, remember, Joker had had his kisser removed because... reasons? Well, because he's the Joker.

In "Suicide Squad" #7 (by Adam Glass, Clayton Henry, Ig Guara and Scott Hanna), she gets to the face and also captures her teammate, Deadshot. She then freakishly puts the Joker's face on the handcuffed Deadshot and sits on him as she talks to him as if he is the Joker. It's beyond twisted.

2 HER MAN, HER MONSTER

"Gotham City Sirens" was an ongoing series about Catwoman trying to follow her own redemption by helping Harley Quinn and Poison Ivy also redeem themselves for their past villainy. The three women tried to be heroes... of a sort. As the book was wrapping up, however, things took a dark turn. Harley breaks into Arkham Asylum to murder the Joker in "Gotham City Sirens" #21 (by Peter Calloway, Andres Guinaldo and Lorenzo Ruggiero). She goes over all the awful memories that she has of their times together, but in the end, he has just too much of a hold over her. She ends up giving in and instead joining up with the Joker and springing him from Arkham by starting a riot and escape. A number of innocent guards are killed.

Poison Ivy confronts her, asking her to choose between her and the Joker, and Harley goes with "Mistah J." It was heartbreaking to see Harley's redemption thrown away after all she had done. At least her current series (as shown above) ended up with a more satisfying visit to the Joker in Arkham.

1 HEY KIDS

"Detective Comics" #23.2 was part of DC's "Villains Month," and it took place right before the Jimmy Palmiotti and Amanda Conner "Harley Quinn" series. This was odd timing, to say the least, as this spotlight on Harley by Matt Kindt and Neil Googe ended up bearing no resemblance to the Harley who was going to appear in the ongoing series. In this one-off issue, Harley is dealing with her sudden freedom from the Suicide Squad following the invasion of Earth by the Crime Syndicate.

Throughout the issue, Harley talks about how you have to put certain aspects of yourself into boxes that you then seal off. However, her psychiatrist self, Harleen Quinzel, is trying to break out a bit. So Harley seals that box off through a plot that involved handing out free video games to a bunch of children and then, at the end of the issue, setting off an update in the games that turns them all into miniature bombs. As they explode all over Gotham, Harley doesn't react -- she just puts it into a box. A comic that ends with Harley murdering a whole bunch of innocent children; doesn't get much more messed up than that.

What do you think is the craziest moment for Harley Quinn? Let us know in the comments!