If you haven't been infected by The Walking Dead yet, there's a good chance you are already a zombie. Or don't have a TV. In either case you are missing out and should probably get with the herd, because it's only going to get better now that the show is back for its seventh season. That is unless you want to be the only roamer around the water cooler not discussing Lucille's next victim.

There's a lot we know about TWD. Like it's the greatest show ever to feature cannibalism, Johnny Depp's decapitated head, chocolate pudding and a little boy getting shot in the eye. Also, that Rick Grimes is a badass. But there are still plenty of off-screen trivia and on-screen easter eggs that even the most loyal of walkers have yet to sink their teeth into.

Here are 15 Things You Didn't Know About The Walking Dead.

15. HBO Passed Because the Show was Too Violent

The network that has shown Khaleesi eating a heart, a pregnant lady stabbed to death and is not above having a brother rape his sister, felt The Walking Dead was just too violent for their viewers. Originally, the show's creators pitched their idea to all the big players, and HBO, one of the most obvious fits, passed. They were willing to take it on only if the producers would significantly cut down on the violence. Because imploding a man's skull? That's fine. But doing the same to a zombie, that's just not cool.

Come to think of it, AMC has made a career out of devouring HBO's throwaways. Both Breaking Bad and Mad Men were turned down by them, though for vastly different reasons. Of course, that doesn't make a network built on a foundation of nudity, violence and vulgarity finding The Walking Dead too extreme any less odd. Luckily, AMC on the other hand has no such qualms about seeing a zombie torn in half or whatever other grotesqueries the show can dish out, just so long as no one swears while they do it.

14. The Opening Logo Has Been Decaying Since Day One

After watching a show for long enough, it's only natural to start zoning out during the opening credits; you might even find yourself fast-forwarding through them more often than not.  But more than likely, even the most casual of viewers have noticed that The Walking Dead's main title sequence changing over the years. From the photos of Shane and Lori in Season One to symbolic objects like badges, watches and arrows in later seasons, the credits have definitely mixed things up over the years. But one of the coolest evolutions to keep an eye out for is the ever-changing main logo, which has been getting darker, grimier and all-around more worn out from one season to the next.

Just like the walkers themselves, who are gradually rotting from the inside out, the logo is another sign of the showrunners' dedication to creating an atmosphere of a deteriorating society. Which begs the question, with the series' continually being renewed, what will be left when all is said and done?

13. Networks Originally Wanted it to be a Zombie Crime Procedural

Before AMC came along and revived our interest in a zombie apocalypses, networks were reluctant to jump on board. In the years leading up to the series' 2010 premiere, producer Gale Anne Hurd and original showrunner Frank Darabont had a rough go of it when they went around pitching Robert Kirkman's graphic novel based on the world surviving an epidemic of walking corpses who eat people. The folks over at NBC finally offered to take it on at one point -- so long as they left out the zombies.

Your guess is as good as ours as to what that would have looked like. Luckily, this idea fell dead, only to be replaced with an even more ridiculous one...turning the show into a “crime-of-the-week” procedural in the vain of Law & Order and CSI, only with zombies. That's right readers, each week, Rick and Co. would solve a zombie related “crime” that would not only help provide a better understanding of human nature (somehow), but also answer the question that's constantly on viewer's minds: what exactly are the walker's motives for eating those brains? Darabont politely declined and then ran away as fast as possible, because nothing will turn you into a mindless vegetable quicker than watching Chris O'Donnell and LL Cool J chase down criminals on a weekly basis.

12. The Show Might Exist in the Same Universe as Breaking Bad

Who doesn't love a good in-world crossover? Imagine it was revealed that Disney's Anna and Elsa are related to Tarzan, or that Daredevil and the Ninja Turtles were created in the same accident. Just as mind blowing is the possible connection between two of AMC's most popular shows.

You may have recognized the blazing red Dodge Challenger Glenn steals during Season 1 as the same vehicle Walter returns to a car dealership managed by a guy (wait for it) named Glenn. Or that Daryl's brother Merle has a stash of drugs clearly containing some of Walter White's trademark Blue Sky meth. Adding to the link, Daryl tells Beth that his brother knew a drug dealer who was a “janky little white guy” that had a penchant for using the word “bitch.” Or as we like to call him, Jesse Pinkman.

Now, this connection has never been officially confirmed, and the fact Breaking Bad was set in Albuquerque, New Mexico while The Walking Dead takes place in and around Georgia puts some distance between the two. But we're convinced they live in the same universe, and we're eagerly anticipating the spinoff showing how that car got all the way to Atlanta.

11. Dale Asked to Be Killed Off the Show

The Walking Dead is known for unexpectedly killing off its main characters, so much so you never know who's going to be next. Sometimes, even the writers are caught off guard, like when Jeffrey DeMunn asked that his character Dale be written off the show after the actor was offended that his friend and show creator Frank Darabont was fired midway through Season 2.

Being the versatile team they are, the show's writers obliged, and instead of having Carl's pet walker kill Hershel as originally intended, they swapped in Dale. As the moral center of the group, the loss of Dale left a big hole, but luckily, in turns out that all old silver-bearded white guys are interchangeable, and Hershel could easily be adapted to fill the future role Dale was to play throughout the series. All's well that ends well, because no one could get their head chopped off with a samurai sword like Hershel.

10. Daryl Was Created for Norman Reedus After He Auditioned for Merle

Fans of The Walking Dead comics are well aware that the character of Daryl is not from the book, and was created specifically for the TV show. Arguably the most popular survivor, it was a good thing they did, but why deviate so far from the original material? Because Norman Reedus is awesome.

Originally, Reedus auditioned for the role of Merle (who also didn't exist in the comics) and was passed over for the part in favor of Michael Rooker. But TWD writer Robert Kirkman was so impressed by the former Boondock Saints star's performance that he created the role of Daryl Dixon just so Norman could be on the show. It's not everyday an actor nails a tryout so much that they come out with a brand new character tailor-made for their talents. But that's just the type of bullseye we've come to expect from Mr. Reedus. Which is why it's a shame he's such a strong contender to die this season.

9. Carol Was Supposed to Die Instead of T-Dog

In another instance of an unintended character death swap, T-Dog was never meant to die -- at least not as early as he did. During the Season 3 walker takeover of the prison, it was Carol who was supposed to meet the horrible fate that T-Dog suffered. The switch had nothing to with creative differences and everything to with behind-the-scenes drama. Namely, no one could stand T-Dog.

The show's producers were growing annoyed with actor IronE Singleton, who routinely showed up late for shooting and had an increasingly negative attitude as the seasons progressed. Though the script called for the then-milquetoast Carol to get eaten alive during the attack, it was ultimately decided that T-Dog needed the ax. So when the time came, it was decreed he would sacrifice himself to save her, paving the way for the once-in-a-lifetime opportunity of Melissa McBride developing Carol into a middle-aged, female Rambo.

8. The Show is Shot on 16mm Film

This one's for all the film nerds out there. In this technical age of iPhones, HD DSLRs and RED cameras, it's often assumed that everything that hits the big screen or our TV sets is filmed digitally. After all, it's cleaner, crisper and more colorful, not to mention a hell of a lot cheaper. So why wouldn't everyone want to go this route? Because zombies look cooler on film.

Although they tested everything from HD to 35mm, the showrunners opted to shoot The Walking Dead on Kodak's Super 16mm, and they've continued to do so to this day. It was revealed these behind-the-scenes decisions were made due to the smaller gauge and grainy look perfectly matching the tone of the series. Not to mention the lack of control and smaller size of the cameras allowed for a more creative, gorilla style of filmmaking that lends itself well to the unpredictability and up close feel of the show. And as an added bonus, all that zombie makeup appears a whole lot more disgusting when its not crystal clear.

7. Rick Always Carries Around the Bullet That Killed Lori

The moment when Lori realizes she's going to die giving birth to baby Judith and asks Carl to kill her is one of the most heartbreaking moments from the series. When Rick finally sees Carl and realizes his wife is gone, he understandably goes on a rampage through the prison and starts talking to dead people on the phone. But right before all that craziness, Rick visits the spot of her death, where he finds the bullet that Carl shot his mother with and places it in his pocket.

Executive producer Greg Nicotero has mentioned that Andrew Lincoln always carries this bullet while playing Rick. This may be to help the actor get all method-y and stay in focus with his character, or perhaps the bullet will pop-up again in a future episode, who knows? Regardless, it's evidence that Rick carries around his grief over Lori's death everywhere he goes. And despite having recently shacked up with Michonne, he never forgets what he's lost.

6. Negan Was Inspired by Henry Rollins

As any reader of the comics know, and viewers of the show will surely find out soon, Negan is a lot of things, most notably a foul-mouthed, baseball bat-wielding psychopath. So how do you come up with a ruthlessly vile yet disarmingly charming character like that? By finding someone just as likably wild to base him on. Which is exactly what Robert Kirkman and comic artist Charlie Adlard did.

While there's no disputing Jeffrey Dean Morgan has owned the character, originally, many wanted the part to go the man that inspired him in the first place: punk rocker-turned-actor Henry Rollins. Though we think things turned out just fine, we'll take every splinter of Negan's backstory we can get. And we're not the only ones who find ourselves liking Negan way too much. Kirkman originally intended to kill off the leader of the Saviors shortly after he was introduced in the comics, but he ended up falling in love with the character and making him the central antagonist of the series instead. Which means there's going to be a whole lot of Lucille in our future.

5. You Can Buy Daryl's Crossbow at Walmart

Messy wig that annoyingly covers your eyes? Check. Winged leather jacket inspired by the movie Castaway? Check. Constant skeptical stare and seven years worth of surprisingly short chin hair? Double check. Now all that's left is to top off that perfect Daryl Dixon Halloween costume with a real deal Horton Scout HD 125 crossbow. Yep, that's right. For just over 300 bucks, you can buy the very weapon everyone's favorite redneck uses to shoot zombies in the head at Walmart. Walkers not included.

Now we can't guarantee you'll be as cool as Norman Reedus -- or that you won't shoot yourself in the foot -- but it's not everyday you get to own the same iconic weapon as a beloved fictional character. Just ask all those wannabe Jedis. So the next time you're rummaging through the $5 movie bin at Walmart, why not also pick up something that just might come in handy the next time your neighbor is getting their brains eaten.

4. Thomas Jane Almost Played Rick

There's a lot of things you might not know about Andrew Lincoln. For one, his grizzly Southern accent is fake (Lincoln is from the UK). For another, his real name might beat out Benedict Cumberbatch's for the most British sounding name ever (it's Andrew Clutterbuck). And yet, these days, it's impossible to imagine anyone else as Rick Grimes. But would we be saying the same thing of Thomas Jane if he had gotten the part as originally intended?

Originally, the show's creator, Frank Darabont, had planned on casting Jane in the role, who he'd worked with on The Mist. This would have rounded out the additions of Laurie Holden (Andrea), Jeffrey DeMunn (Dale) and Melissa McBride (Carol) to the cast, all of whom also appeared in that film. Eventually, Clutterbuck strolled in and blew everyone away his with his British awesomeness, but for a time, Rick Grimes was going to played by a former Punisher. Some fans believe this was referenced early on in Season 1, right after Rick kills his first walker and the blood splatter on his shirt stains in the shape of a skull.

3. The Source of the Outbreak Will Never Be Revealed

For all those who like definitive answers and hated Lost, you'll probably come away unsatisfied when The Walking Dead finally eats its last victim. Though Robert Kirkman has dispelled any theories that the series is a dream, during a panel for this year's New York Comic Con, he outright stated, “I'll never reveal what the source of the outbreak is in the comic.”

None of that means that the show will follow suit, of course, as we've seen the series deviate from its source material on a number of occasions; not to mention the fact that Kirkman has said that the two will end differently. They've already delved into some of the background when the group met Dr. Edwin Jenner at the CDC and it was revealed that the entire planet is already infected. (Though Kirkman has admitted that he wished they had never shared that secret and regrets the entire final episode of Season 1). Given that nothing close to a true explanation for the outbreak has been suggested since -- Eugene's wild goose chase from Season 4 notwithstanding -- the show will most likely follow the comics and never tell audiences what brought about the end of the world. Because The Walking Dead isn't really about knowing why flesh-eating zombies exist, it's about seeing Rick bite people's necks off.

2. Carl's Stunt Double is a 31-Year-Old Woman

Ever thought Carl acts like a girl? Well, you're sort of right, because sometimes he is a girl. It's no surprise that the cast of The Walking Dead uses stunt doubles, with all their falling off bridges in cars and running with sharp objects. And 17-year-old actor Chandler Riggs is no exception.

Which is why if you've ever watched the show and could swear Carl looks exactly like a girl, you just might be looking at his stunt double, who's a woman in her thirties named Emily Brobst. Of course, Carl hasn't always been the size of a tiny grown woman, which is why prior to Season 4, Savana Jade Wehunt filled the role, who was in her early twenties at the time and also played the The Governor's zombie 11-year-old daughter. But Kudos to Brobst for looking so fantastic for her age that she can easily pass off as a teenager, despite having been born during the Reagan administration.

1. The Real Hero of the Show is a One-Eyed Dog

The Walking Dead is filled to the brim with memorable characters, ranging the entire gamut from evil to gallant. None, however, are as heroic as Dooley, the one-eyed dog. Fans of the show (and dogs) might remember the thirteenth episode of Season 4, when Daryl sets up some noise traps around an abandoned funeral home to safeguard him and Beth, only to have a mangy canine set them off. With his one good eye and long scraggily hair, Dooley fits the look of an apocalypse survivor to a tee.

In real life, Dooley lost his eye while saving his owner from a violent carjacker. While the actors on The Walking Dead might pretend to help one another from flying bullets and wayward wooden bats, Dooley here is actually saving the world one owner at a time, and he has the scars to prove it. Now that's who we'd want on our side during the next zombie apocalypse.

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Are there any other undead facts walking around out there that we missed? Let us know in the comments.