One of the interesting things about Deadpool is that the character was around for almost two decades before he became what you would call an "R-Rated" character. Up until 2007, the violence in Deadpool's comics was strictly at a PG-13 level, so despite Deadpool having very strong healing abilities, his injuries tended to be a bit subdued.

RELATED: Oh Man, Logan: Wolverine’s Most Brutal Injuries

Once he became a title for "mature readers," the violence in the comics began to escalate, with writers coming up with more and more gruesome injuries for Deadpool to recover from. Here, we will take a look at the most gruesome injuries that Deadpool has ever suffered. We're only referring to "in-continuity" stories here -- whatever slight limits the comics place on Deadpool in-continuity are gone with the out-of-continuity tales, so it really wouldn't be fair to compare the two.

15 ARROWHEAD

The 2008 "Deadpool" series launched in conjunction with "Secret Invasion," with Deadpool hunting down Skrulls. Soon, though, he found himself on the wrong end of a deal with Norman Osborn, who took over SHIELD following "Secret Invasion" in the over-arching Marvel event generally referred to as "Dark Reign." Osborn had his own team of Avengers (their series was called "Dark Avengers") where he would have supervillains dress up as Avengers, with Venom being Spider-Man, Moonstone being Ms. Marvel, Daken being Wolverine and Bullseye being Hawkeye.

After an earlier fight that didn't go Osborn's way, Osborn sent Bullseye (as Hawkeye) after Deadpool to finish him off once and for all in an excellent three-part story in the pages of "Deadpool" #10-12 (by Daniel Way, Paco Medina and Juan Vlasco). The two characters had a history with each other, and their cat-and-mouse game was thrilling. At one point, Hawkeye/Bullseye showed off his sense of humor by doing the ol' "arrow through the head" gag, only literally this time, with Deadpool getting an arrow through his brain, his senses were dulled, his mind scattered and he even picked up a local mental health radio show until the arrow was removed. It was very Deadpool.

14 KICKED HIS AXIS

In his first mission with the Uncanny X-Force, Deadpool and his new teammates debated whether it was okay or not to kill a young boy who was cloned as the eventual new host body for Apocalypse. Is it okay to kill an innocent kid if you know he's going to grow up to be an evil guy? Ultimately, Fantomex answered the question by shooting the boy in the head. Fantomex, though, then cloned the boy and raised him in an accelerated aging virtual reality, as Fantomex wanted to know if he had made the right decision or not. Ultimately, the boy, dubbed Evan, was broken out of his program and went to live with the X-Men, where they trained him to be a hero (he ultimately chose the hero name "Genesis").

During the crossover event, "Axis," a group of X-Men and Avengers (and their respective supervillains) were all caught up in a magic spell where their personalities were inverted. Good guys became bad guys and bad guys became good guys. In the case of the neither bad nor good Deadpool, he instead became a pacifist (calling himself "Zenpool"). Evan was turned evil and embraced his Apocalypse heritage, fighting Zenpool and ultimately tearing his head right off of his shoulders in "Axis" #7 (by Rick Remender and Adam Kubert)! Luckily, the body-less Zenpool continued to work on Evan and eventually got him to find his inner good self.

13 HEADHUNTED

As noted earlier, when "Dark Reign" began, Deadpool and Norman Osborn were at odds with each other. This first came into full view in a crossover between Deadpool and the Thunderbolts in "Deadpool" #7-8/"Thunderbolts" #130-131. The Thunderbolts had been a team of supervillains that were under Norman Osbron's direction that hunted down unregistered superheroes following "Civil War." Once Osborn became the head of SHIELD, his original team of Thunderbolts became the basis for his Dark Avengers. So, he then formed a new team of Thunderbolts to do black ops missions for him.

One of their first missions was to kill Deadpool before Deadpool killed Norman Osborn. The fight between Deadpool and the Thunderbolts led to a number of injuries for Deadpool (including him shooting himself a few times when the Thunderbolts' Ant-Man got into Deadpool's costume and started running amok). In the end, though, in "Thunderbolts" #131 (by Andy Diggle, Bong Dazo and Joe Pimentel), it was the Thunderbolts member known as the Headsman who ended the conflict by cutting off Deadpool's head with an ax. Osborn was temporarily relieved... until he later learned that Deadpool could live even without a head, at which point he sent Hawkeye/Bullseye after Deadpool.

12 REACH OUT AND TOUCH SOMEONE

Deadpool had a little fun with the concept of re-numbering comic books whenever they reach milestones by re-numbering "Deadpool" at #900 for a special one-shot issue that was filled with short stories. The opening one was by Jason Aaron, Chris Staggs and Juan Vlasco and it was Aaron's take on the rather familiar story of aliens abducting people. This time, it was Deadpool who got abducted and things did not go smoothly.

First, the aliens used a rather large anal probe on Deadpool, but then he shocked them. He appeared to be chewing on his restraints, but in reality, he was chewing through his own arm! He then used his bitten off arm to attack his abductors, leading to one of the most gruesome, yet awesome punches a comic book character has thrown this side of Arm-Fall-Off-Boy! Deadpool then proceeded to kill all of the aliens on the ship, using the drill that was used for the probe on a number of the aliens.

11 TASTES GREAT, LESS FILLING

In the aforementioned opening arc of "Uncanny X-Force" (by Rick Remender and Jerome Opena), Deadpool and his teammates took on the cult of Apocalypse, who were raising a young clone to be the next host of Apocalypse. The group also opened up the ultimate four horseman of Apocalypse, as Apocalypse's aide -- a man named Ozymandias -- had plucked four mutant beings from various points of history and brought them all together as the Final Horseman of Apocalypse.

During their battle with the Horsemen, two members of X-Force -- Deadpool and Archangel -- were affected by the Horseman known as Famine. They became emaciated and passed out from hunger. Deadpool's healing powers kicked in, though, and he was able to keep himself from being killed. He then came up with an out-of-the-box approach to helping Archangel's hunger -- he began cutting pieces of himself off and feeding them to Archangel!! It was gross, but it was effective!

10 TUG OF WADE

"Deadpool Annual" #1 (by Ben Acker, Ben Blacker and Doc Shaner) was a game-changer in the history of Deadpool. It revealed that the extra narrative box that existed throughout the previous volume of "Deadpool" was the result of Deadpool being merged with Madcap at some point in the past, when Thor blasted Deadpool and Madcap to dust with some lightning. They ended up reforming as one being, with Madcap's mind being mixed with Deadpool; hence, the extra narrative box for Madcap's thoughts.

The Annual showed how Deadpool managed to convince Thor and Luke Cage (after Madcap first used his weird powers to make them each think that they were on "So You Think You Can Dance") to play a game of tug of war with his body, tearing it into two, with one side reforming as Deadpool and the other side reforming as Madcap. As it turned out, though, the experience left Madcap in a strange place and he has since become Deadpool's greatest nemesis.

9 HEY MAN, NICE SHOT

Daniel Way's "Deadpool" was a fascinating series, as he balanced the over-the-top cartoon violence with an also ever-present feeling that Deadpool was dealing with severe depression. That feeling came into play at the end of the previously mentioned Deadpool vs. Hawkeye/Bullseye arc. Throughout the fight, while he was trying to kill Hawkeye/Bullseye and Hawkeye/Bullseye was trying to kill him in return, he felt really alive. He even got to wear a suit of armor made entirely out of meat, which apparently was something he had always wanted to do.

In the end, though, Hawkeye/Bullseye came up with a way that they could resolve the situation. He would pay Deadpool to pretend to be dead so that Norman Osborn would get off Hawkeye/Bullseye's back with the whole "you have to hunt Deadpool down" thing. Deadpool agreed and he sat down to relax, but then he realized that without the thrill of the fight, he didn't really know what to do with himself, so just for the sake of doing something, he blew his own brains out! Very dark stuff.

8 THAT'S A SPICY MEATBALL!

Deadpool has had a very strange relationship with the heroes currently known as the Great Lakes Avengers. Early in his first ongoing series, he fought them when they were going by the Lightning Rods (naming themselves after the Thunderbolts, before they learned that the Thunderbolts were secretly the Masters of Evil). That battle ended up with Deadpool traveling through time to an old issue of "Amazing Spider-Man" (still probably the highlight of Joe Kelly's run on "Deadpool").

During "Civil War," Deadpool and Cable split over their views of the event, with Cable serving with Captain America in the resistance and Deadpool hunting down un-registered superheroes. Deadpool took on the Great Lakes Avengers in "Cable and Deadpool" #30 (by Fabian Nicieza, Staz Johnson and Klaus Janson). During the battle, Deadpool unleashed a grenade on himself, leading to a caved in chest that was super gross. In the end, it turned out that the Great Lakes Avengers actually had already registered, so the whole fight was just pointless!

7 SUBTLE AS AN ANVIL TO THE HEAD

After "Deadpool" #900 came out, Marvel then launched a "Deadpool Team-Up" series that counted backwards from #900, with each issue having Deadpool teaming up with different Marvel characters with different creative teams handling the issues. In one of the final issues, Rick Spears, Philip Bond and Daniel Brown delivered "Deadpool Team-Up" #885, which saw Deadpool team-up with an obscure character from Steve Gerber's "Man-Thing" run in the 1970s -- Hellcow, the vampire cow!

A Doctor Killgore had been keeping himself alive by drinking from the milk of Hellcow, but it was not enough, he was still dying. So, he wanted to access Deadpool's healing powers, as well. He first had to capture Deadpool, and to do so, he sent an anvil swinging towards him. It missed Deadpool at first when he bent over to pick up a four-leaf clover, but after Deadpool stood up, it got him on the way back, in all of its violently disgusting glory.

6 DEADPOOL-KABOB

As we noted earlier, it was not until late in the first decade of the 2000s that "Deadpool" comics began to get really disgusting with their violence, so this sort of stuff is less than a decade old. However, there were the rare exceptions in his first series that could hang with some of the more violent imagery that would occur later on in the series. One of these exceptions was "Deadpool" #27 (by Joe Kelly, Walter McDaniel and Whitney McFarland), where Deadpool had been seeing another old Steve Gerber creation, the oddball Doctor Bong.

Bong told Deadpool that for the sake of their therapy, he needed to partake in a classic comic book example of a guest-star coming to fight Deadpool. As luck would have it, Deadpool ran into Wolverine and Kitty Pryde. Wolverine would not fight Deadpool, so Deadpool then sucker-punched Kitty Pryde in the face, leading to Wolverine attacking him. Deadpool kept trying to make Wolverine angrier and angrier until Wolverine's berserker mode kicked in and he basically disemboweled Deadpool, which oddly enough, did lead to a breakthrough in Deadpool's therapy! Doctor Bong was right after all!

5 A CABLE THROUGH TIME

"Deadpool vs. X-Force" was a strange miniseries by writer Duane Swierzynski and artist Pepe Larrax that dealt with Cable and X-Force fighting Deadpool in a story set before Deadpool first met them all in "New Mutants" #98. It was a time travel story, as Deadpool was traveling through American history, causing chaos in the past, chaos that Cable and his crew had to go back and try to stop (it was particularly fun seeing Cannonball try to stop actual cannonballs during the American Revolution).

Deadpool and Cable fought one on one, but since Deadpool didn't know Cable had telekinetic powers, he thought that he had Cable under control when he took over Cable's bionics. With his telekinesis, though, Cable broke free and unleashed an assault of bullets on Deadpool, basically turning Deadpool to mush. Of course, this is Deadpool, so he was back causing trouble within the span of a couple of pages!

4 HULK SMASH!

As we noted earlier, Deadpool was dealing with some mental health issues in Daniel Way's "Deadpool," and it came to the forefront in a storyline where Deadpool decided that he really wanted to die. However, his healing powers prevented that from actually happening. He kept coming up with ideas and they kept failing. One of his ultimate ideas came in "Deadpool" #39 (by Daniel Way, Bong Dazo and Joe Pimentel) where Deadpool set off a couple of nuclear warheads on the Hulk.

This naturally led to the Hulk becoming enraged, and Deadpool kept him in close pursuit, continuing to try to enrage the Hulk to make the Hulk stronger and also more willing to kill Deadpool. In the end, the Hulk was provoked far enough that he finally unleashed on Deadpool, punching him into just a bunch of bloody pulp. However, tragically that wasn't enough, and Deadpool healed up and was then sentenced to a mental hospital.

3 KEEP ON TRUCKIN'

At the end of "Deadpool vs. Carnage" #2, Deadpool had tracked down Carnage and his lady, Shriek, as they were driving down the highway. Deadpool hit them head-on with a combine, which seriously injured Shriek. This naturally set off Carnage, who was already a psychopathic murderer and would inevitably lead to unbelievable levels of violence.

In "Deadpool vs. Carnage" #3 (by Cullen Bunn and Salva Espin), Deadpool and Carnage battled while Deadpool mocked Carnage's obsession with chaos, by pointing out that "chaos" was not an actual thing, but rather just whatever Carnage wanted it to be, so he was not really "following" anything. Carnage responded by digging his tendrils into Deadpool and then flinging him into a semi-truck, which then proceeded to ride over Deadpool, crushing him one wheel at a time. Of course, once again, this is Deadpool, so he was literally walking again on the next page (albeit with his guts hanging out of his stomach).

2 AN ELEPHANT NEVER FORGETS

The opening arc of Gerry Duggan, Brian Posehn and Tony Moore's "Deadpool" run involved a sorcerer bringing back the spirits of all of the dead Presidents of the United States and setting them against the United States. S.H.I.E.L.D. turned to Deadpool to help them fight these demons, as Deadpool's healing powers came in handy against the powerful destruction caused by the ghosts of the dead presidents.

It was a wonderfully bizarre thing to see Deadpool fight against twisted versions of the most famous men in American History, and in "Deadpool" #2 (by Duggan, Posehn and Moore), Deadpool took on the ghost of Theodore Roosevelt. Roosevelt was a famous animal-lover, so he set a zoo after Deadpool, leading to a shocking attack where Deadpool is gored by an elephant. Deadpool managed to use the elephant's trunk to wrap up Roosevelt. He then sent Roosevelt toward a power line, but the elephant wouldn't let go and the ghost and the elephant were both electrocuted.

1 PURE CARNAGE

The conceit behind "Deadpool vs. Carnage" was a strange one. In the first issue, Cletus Kasaday was at a midwest diner when he saw a cop. He ended up slaughtering everyone in the diner. Deadpool was in New York City when he saw the news and as he was clicking through the various TV channels covering the massacre, the voices spoke to him and let him know that he was destined to be the person who finally took Carnage down.

In "Deadpool vs. Carnage" #3 (by Cullen Bunn and Salva Espin), after Carnage threw Deadpool into the truck and a crowd of people gathered around Deadpool, he only heard in their voices a message to keep after Carnage. So he continued to confront the villain, which led to Carnage literally tearing Deadpool into little pieces. Deadpool got the last laugh, though, as after Carnage similarly slaughtered a team of soldiers using symbiotic weapons, the symbiotes transferred to Deadpool, who then defeated Carnage using the symbiotes by disguising Shriek as Deadpool, leading Carnage to assault her, which caused him to snap.

What do you think was the most gruesome injury you've seen Deadpool suffer (and survive)? Let us know in the comments section!