Zatanna Zatara dates back to the 1960s, the daughter of Giovanni Zatara, one of the most gifted magicians of his time and a member of the mysterious "Homo magi" race (a subspecies of humans with a natural inclinations toward magic). Zatara was actually a Golden Age superhero from the 1930s, but for Zatanna's story, he vanished without telling her the secret of his powers. Growing up as a stage illusionist, she didn't discover her powers until she went on the hunt for her father. This search was a multi-comic story, where Zatanna appeared in Batman, Hawkman, Green Lantern, and other comic books for a single-issue guest slot. Very advanced crossovers for the 1960s!
So what exactly are her powers?
EVERYTHING! Her magic is just that... magic. She speaks a sentence backwards and alters reality to suit her purposes. In most cases this would make her horribly overpowered and easily resolve any plot device put in her way. It makes writing her tricky... but there's a lot of ways to get around it, from stealing her voice, losing her powers, or just putting her up against problems that can't be solved with a wave of the hand.
She ended up joining the Justice League during the 70s, during which point her powers were taken away - or, at least, limited to the four elements. It was reversed relatively quickly because, come on, that's lame. She made relatively frequent appearances throughout the 80s and 90s, but because of the trend toward dark and gritty, the relatively "silly" backwards spells made her unappealing to most writers.
However, things got big for Zatanna in 2004, during Identity Crisis (which was terrible and you should never ever read it). In essence, Dr. Light rapes Sue Dibny (ugh) and ultimately the League votes to wipe his mind. Zatanna is the one to do it, despite close debate as to the ethics. It drives a wedge between her and the team, and she quits/is fired. Eventually, it's retconned that Zatanna makes a habit of these mindwipes; Catwoman finds out her turn to the straight and narrow was because of Zatanna! It pisses her off obviously, but they patch it up; she ends up with the Seven Soldiers of Victory and a few other magical organizations. Oh, and her cousin Zachary Zatara was introduced a few years ago as a member of the Teen Titans. He's pretty alright.
Since then, she's had a lot of appearances in DC's Vertigo line - hard-edged, mature stories (GOOD mature stories, not just blood'n'guts schlock) with a serious edge. She's banged John Constantine is what I'm trying to say. I mean, not that I blame her, John Constantine's the man. But she's had some trouble treading the line between the two universes, which tend to stay SOMEWHAT separate.
With the post-Flashpoint New 52 - a complete retcon of the entire DC Universe, rejiggering every character and their histories - she's ended up as a member of Justice League Dark, which contains a number of more mystic DC characters and a touch of Vertigo to boot. It's supposed to be pretty alright. Her new costume is cool (in the picture above), too, even if it's not quite up to par with her classic magician's outfit.
Zatanna has become a pretty huge supporting member of Batman's cast (as you may have gathered from her relationship with Catwoman). This is partly due to Batman: The Animated Series, which had an episode featuring Zatanna. She and Bruce (in his pre-Batman years) both trained under Zatara, which is how Batman got so good at vanishing and such. She wasn't magical, just an illusionist, but it was still a good episode. Thank writer Paul Dini for that - he's got a MASSIVE hard-on for Zatanna. He even married a magician! She's hot, too.
This was eventually transmitted to the comics, where she and Batman have been romantically linked (to an extent; it never quite works out because he's Batman and devoted to the cause and all that). But, still, she's becoming an honorary member of the Gotham crowd, making appearances in Gotham Sirens and all that.
Since then, outside of comics, Zatanna's popped up in Justice League Unlimited (where she was upped to fully magical), the Gotham Girls webseries, and Batman: The Brave and The Bold in a cold opening. She almost got her own flash-animated show from Cartoon Monsoon, but it wasn't picked up beyond the pilot. Oh, and she'll be appearing on Young Justice next week... Zatara is a member of the Justice League, and rumor has it she'll end up with the Young Justice team.
On the live-action side, she had a movie in the planning stages a few years ago, but like most DC movies, it's probably dead in the water by now. On TV she got a recurring role on Smallville, where she's KIND of a bad guy, I think. She comes into conflict with Clark, at least, though she learns her lessen and becomes good by the end. Never really watched the show, but the actress is pretty hot, right?
Anyways, Zatanna is one of my personal favorite superheroines. She's got a great schtick, with enough flexibility to fit her into any story but enough of a limit to keep her from overpowering the story. I particularly like the "novice magician" line, which I hope they end up using in Young Justice. Not to mention the costume (come on, sexy magician, can't go wrong) and the generally sense of the character - not too serious, not too slutty, but a fun adventurer sort of character. A nice contrast to Batman in particular, for a number of reasons.
BUT YEAH, there's Zatanna. Thoughts?