I wrote this many years ago as a wee homage to the lovely Miss Quinn.  This is firmly grounde within the animated universe as it was then, prior to The New Batman Adventures so is quite dated, but I still kinda like it..

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On September 11, 1992, Joker made his debut into the Animated World of Batman in the episode 'Joker's Favour'. With him, he brought one of the brightest, and freshest young characters the Bat-Universe has ever seen!
Harley Quinn, a.k.a, Dr Harleen Quinzel made an immediate impact on all those who watched her, and her popularity grew to extreme heights; indeed she has become as popular as The Joker himself.
The man behind the harlequin is Paul Dini, reputed comic book writer, and co-producer of Batman: The Animated Series According to Dini, Harley was originally a one-shot character: "I needed the Joker to have an assistant/moll of some kind. The more I worked with the character, the more she seemed to take on a life of her own".

Dini got the inspiration for Harley from his old college pal, Arleen Sorkin, known for her role as Calliope Jones Bradford in the long-running daytime soap, DAYS OF OUR LIVES. Dini "saw her playing a clown-like character... that sort of cemented Harley for me".
Bruce Timm provided the character design, making Harley petite, athletic, sexy, childlike and crazy. Not surprisingly, there's an uncanny resemblance to Arleen there. Even less surprisingly, Arleen provides the voice for the character. With Dini's brilliant writing, Timm's divine art and Sorkin's wonderfully sassy voice, Harley has become a fun-inspiring, sympathetic, lovable, yet wicked villain, a firm pillar of the Batman Community. "I was born to play her,” says Sorkin.

Harley's major character motivation is her over-whelming obsession with The Joker. Whilst she can survive as a character on her own, and carry a story line by herself, Harley's Universe begins and ends with him. It is the tie-in factor that keeps her a bad guy. Says Dini: "After Bruce and I had done a couple of shows with Harley, we began thinking, what if she's really kind of stuck on him and that's part of the relationship. She's in love with him and he treats her like a pet".
True - and Harley's affectionate nature seems to have reached even The Joker himself, though he'd be the last to admit it. While she drives him round the edge, it's uncharacteristically good-natured of him to keep her around. Then again, he could have a more sinister motive... "Harley, in her own warped way, wants to marry the guy, settle down and have this nice little family life. But he'll never give her that because he knows by not giving it to her, he's torturing her in a meaner way than if he actually just shot her".
Aw...but that can't be all. Surely, if Joker found her truly as irritating as he claims, he would have written her off long ago? Maybe deep down inside, he feels all warm and fuzzy every time Harley calls him 'Puddin'"! Maybe…?

At any rate, Harley is going strong, whether trailing behind The Joker on his capers, or performing one of her own, her bright, bubbly nature never fails to bring the fun back to comics and cartoons.
Of course, Harley's existence isn't all sunshine and sparkles - she's got good intentions, but tends to bungle things up somewhat. Not only is she very much insane and wanted in two dozen states, but she just can't seem to please her Puddin', and no matter how he abuses her she just keeps coming back for more. There's a tortured side to Harley that hasn't been fully explored yet - she's a multi-faceted character who's terribly misunderstood, and while you love her to pieces, you rarely see her too down in the dumpers. And when she is, it's heartbreaking. The only problem with the character of Harley being solely confined to the Animated Series Continuity, a children's show, means her character is suppressed somewhat by censors, a problem the other popular characters don't have, existing in the mainstream. The Batman and Robin Adventures, the comic based on the series, allows for more freedom, but not much.

One of the most poignant and fun visions of Harley and her relationship with The Joker came with 1994's MAD LOVE, the Eisner and Harvey Award winning comic by creators Dini and Timm. This comic brilliantly showed off Harley's obsession and undying love for the Joker, her quirkiness, cleverness, her fun-loving and enthusiastic nature, and also the hurting, sad side of her, telling the story of her origin, and rounding her character out inestimably. More Harley stories need to be like this - while she adds that spark of sunshine to stories, constantly appearing like this makes her appear one-dimensional - she needs her tortured woes to add depth to her. Thankfully, this is realised, and can be proven in such episodes as HARLEQUINNADE, HARLEY'S HOLIDAY and HARLEY AND IVY.

Harley's development of character not only adds depth to her, but to The Joker as well. Says Dini: "she was very appealing and she added this other dimension to the Joker." Indeed. In Joker's 50 years of life, Harley is his first long-time girlfriend. It’s hard to imagine Joker carrying on a 'normal' relationship, and accordingly, his relationship with Harley is anything BUT. But they DO have one - and whether he likes it or not, they're bonded together, for as long as she loves him, and he permits her to keep coming back.
And in a way, they have a perfect relationship - Harley's lovable side balances out Joker's inhumanity, they can share things together, yet have enough of a difference to keep the spark of excitement in the relationship, she's a masochist and he's a sadist, Harley is an enabler, Joker is a doer. And no matter what he does, Harley is always there to stand by him - so perhaps The Joker needs someone like Harley too. It won't change who he is, but for those of us who've read deeper Joker stories like KILLING JOKE, know there's more to Mistah J than meets the eye.

"Most of his hench people are pretty expendable" says Dini. Not so Harley. So much not so, she now exists as a character in her own right, even coming with her very own action figure. Yes, Harley has proven herself as a strong enough character to have her own toy put on the market, and not a moment too soon! It partially proves Harley's appeal, and her endurance to the audience. Another example is the letter column of any comic Harley has been in recently - the response is overwhelming.

So it's clear that Harley is here to stay, so what does the future hold for her? Firstly, there's the new Animated Series. Unlike many of the other major characters, Harley did not undergo an image makeover.  She's a little leaner and angular - but basically she's the same psychotic clown girl we all love. And the role that she evolved into, that of a strong standing character, is not going to be overlooked. Says Dini: "MAD LOVE is the official origin of Harley Quinn, so whether or not we do a verbatim adaption of the book or we just tell certain elements of Harley's past remains to be seen". Wow! The first time that's been done in the cartoon, and it's hugely welcomed!

Dini and Timm have some reservations about telling MAD LOVE- mainly in how it will translate to the screen. Both creators are very fond of the story, and wouldn't want it marred in any way. But fans, never fear: "We WILL be doing a detailed story of Harley Quinn and her life which will involve elements of MAD LOVE, if not telling that story outright”. So Harley's future, BTAS wise is set in stone. We’ll be enjoying her antics forever.

What about the mainstream continuity? Not much talk from that side, but when Alan Grant took over editing of SHADOW OF THE BAT he promised a "whole slew of new villains". Ohhh... exciting! Could Harley be amongst them? Fans can only hope - and further hope, if she does make that transition that they have a creative team as talented as Dini and Timm to do her justice.

Wherever Harley ends up, comics fans can be assured she'll be around for a very, very long time to come. She's a unique character, with a unique background, who never fails to keep her audiences entertained. And we all know The Joker can hold that gun to her head, but he'll never, ever be able to pull the trigger! Somehow, she’s got under his skin too!