We’re mere days away from the premiere of Deadpool, a superhero movie that — much like the titular Marvel Comics mercenary it features — is shaping up to be quite unlike anything we’ve seen before in comic-book cinema.

Created by Rob Liefeld and Fabian Nicieza, the character that would come to be known as “The Merc with a Mouth” made his debut in a 1991 issue of The New Mutants and quickly became a popular addition to the Marvel Comics universe. Just six years after his first appearance in comics, Deadpool was given his own solo series that followed the unpredictable, irreverent antihero’s adventures as he sliced, diced, joked, and pondered the nature of his own existence en route to becoming one of the most popular — and most unique — new characters of the ’90s.

Cut to 2016 and we’re on the verge of seeing Ryan Reynolds bring Deadpool to the big screen in an “R”-rated romp that’s already earning rave reviews for its wild, yet seemingly faithful, presentation of one of Marvel’s most unstable antiheroes.

So what’s so special about Deadpool? Well, here are a few things you might find interesting about Marvel’s bizarre, butt-kicking mercenary:

He wasn’t always a good guy (and still isn’t) Deadpool’s moral compass generally aligns with the good guys these days, but it wasn’t always that way. In fact, for much of his early years in the Marvel Comics universe, Deadpool was anything but a hero. A mercenary with a nasty habit of killing his partners and anyone else who got in the way of his target, Deadpool was frequent — and dangerous — foe of Marvel’s mutant heroes. At one point he even kept a blind, elderly woman he called “Blind Al” as a prisoner in his apartment, killing anyone who tried to rescue her while taunting — and possibly torturing — her for an extended period. His temperament eventually shifted, though, and while he’s still a far cry from being a “good guy” in the Marvel Comics universe, he now tends to avoid getting involved in straight-up villainy and often finds himself helping Marvel’s heroes with tasks that require someone with little regard for their own safety or sanity.

His origin is linked to a DC Comics character Around the time of Deadpool’s creation, there was a character in the DC Comics universe that had been tormenting the publisher’s popular teenage superhero team, The Teen Titans. The character was a deadly, sword-wielding mercenary named Slade Wilson who called himself Deathstroke. Sound a little familiar? The similarities weren’t lost on Nicieza, either, who reportedly saw Liefeld’s design for a new character he wanted to call “Deadpool” and told him “This is Deathstroke.” However, instead of shying away from the similarities, they embraced them — even going so far as to name the man under Deadpool’s mask “Wade Wilson.” In the end, Liefeld’s certainty that they could differentiate the character from Deathstroke appears to have paid off, as both characters continue to be prominent players in their respective universes.

He got his powers from Wolverine Like a lot of Marvel Comics characters, Deadpool’s fictional timeline is pretty convoluted. Peppered with retroactively erased storylines, bouts of amnesia, and outright lies that have yet to be debunked, there are few things that comic-book readers know for sure about the mouthy mercenary. Surprisingly, that doesn’t include the original source of his superhuman healing abilities. In Marvel Comics continuity, Wade Wilson agreed to undergo an experimental operation after being diagnosed with an aggressive form of cancer, and was implanted with a key element of Wolverine’s powerful, mutant healing ability. Unfortunately for Deadpool, the mix of mutant healing genes and cancer cells caused all sorts of side effects — including the scar tissue that covers most of his body and some of the mental issues that define his personality now.

This isn’t his big-screen debut Most fans already know this, but the Deadpool movie will be Ryan Reynolds’ second time portraying Wade Wilson in a movie. He previously played Wade Wilson in the 2009 film X-Men Origins: Wolverine, and while the movie itself was pretty forgettable, Reynolds’ performance ended up providing some convincing evidence that a Deadpool movie would not only work, but that Reynolds was the best man for the role. It remains to be seen whether the Deadpool movie acknowledges the events of X-Men Origins: Wolverine, but if it does, you can bet it won’t be kind to the 2009 film.

He’s omnisexual Given Deadpool’s affinity for flirting with anything that has a pulse — along with extraterrestrials without circulatory systems, undead entities, and various other extra-dimensional beings — there’s always been questions about his particular sexy-time preferences. Those questions were answered definitively (okay, semi-definitively) in 2013 when Deadpool series writer Gerry Duggan declared Wade Wilson to be… (wait for it)… omnisexual. His declaration was later confirmed by Nicieza on Twitter, who seemed a little tired of fielding questions about a fictional character’s bedroom habits.

He knows he’s in a comic (and a movie, a video game, etc) One characteristic of Deadpool that’s become a big part of the character’s appeal is his extreme self-awareness in the midst of all the comic-book hijinks going on around him. That’s not to say he’s humble or simply aware of his place in the Marvel Comics universe, but rather that he knows he’s in a comic book and isn’t afraid to use that knowledge to get out of a tough situation. Not only does he have a habit of talking directly to readers, but he occasionally sees fit to read ahead in his own comics so he can get a jump on events. This is one element that the upcoming movie seems happy to bring to the big-screen version of Deadpool, so it will be interesting to see how far they take his habit of breaking the fourth wall.