In professinal wrestling the term "heel" refers to the wrestler portraying the villainous baddie standing opposite the heroic "babyface." 

While the babyfaces pushed as the one's that should be treated, more often then not, the crowd cheers for the heel (I'm looking at you Rock) since everyone loves a good villain.

Too bad the same can't be said for the world of mixed martial arts as, unlike pro wrestling, a fighter pulling a few dirty moves can often lead to a career-ending injury.

So without further ado, here are FloCombat's Top 5 most heelish acts in MMA history.

5. Gilbert Yvel loses his mind and knocks out referee

Photo Credit: USA Today Sports

Gilbert Yvel has not one, not two, but THREE disqualification losses.

The first incident involved fans witnessing the menacing, tattooed-covered heavyweight bite his opponent Karimula Barkalaev (yes, you read that right) a la Mike Tyson. Three years later, Yvel is getting disqualified once again from his now infamous bout against UFC Hall of Famer Don Frye.

During the fight, Yvel repeatedly raked his fingers across his opponent's face and even shoved his thumb into Frye's eyes in an attempt to avoid being taken down

But biting an opponent and gauging an eye was child's play for what followed next.

During his 2004 fight against Atte Backman, the referee attempted to separate the two clinching fighters as they were falling over the ringside ropes. Yvel refused to reset in the clinched position as he continuously swatted the ref away. After a number of unsuccessful attempts to restart the fight, Yvel, being his usual nasty self, decided knocking the ref out with a left hook was a good idea. To make matters worse, he literally kicked the man while he was down.

4. Babalu refuses to release chokehold on unconscious opponent

Jun 19, 2013; Thackerville, OK, USA; Jacob Noe (right) and Babalu Sobral (left) fight during BFC 96 at the WinStar World Casino. Mandatory Credit: Kevin Jairaj-USA TODAY Sports

​At UFC 74, Brazilian submission specialist Renato "Babalu" Sobral faced David Heath. In the first frame, Babalu dominated his American opponent with superior ground-and-pound. In the second round, he opened a cut on Heath's forehead. As blood continued to leak from the ravaged Heath (whose face looked more like hamburger meat than a professional fighter), Sobral secured an anaconda choke. 

With his body failing him and his air supply be squeezed shut, Heath tapped. In the vast majority of cases once fighters feel the tap, they release the submission. Too bad Babalu isn't a normal fighter.

Even though Heath accepted defeat, submitting to the suffocating choke, Babalu continued to squeeze and resisted all attempts from the referee to break the hold. He would eventually release the hold after Heath PASSED OUT due to lack of oxygen.

"He has to learn respect. He deserved that. He called me motherf***er," Babalu said during his post-fight interview
Needless to say, Babalu never fought in the UFC ever again. Additionally, the Nevada State Athletic Commission withheld half of Sobral's $50,000 fight purse.

3. Shinya Aoki snaps opponent's arm and gives the bird

Photo Source: Bleacher Report

Why do you do what you do?

In 2009, the Japanese featherweight was scheduled to square off against fellow icon Tatsuya Kawajiri. But after a last-minute change, much to the chagrin of the now enraged Aoki, he was paired up with Mizuto Hirota. For some backstory, Hirota was coming off a highlight-reel win over Aoki's friend Satoru Kitaoka, earning Sengoku the lightweight championship in the process.

Aoki would go on to snap Hirota's arm with a violent hammerlock early in the first round. With his arm mangled at his side, Hirota could only watch as Aoki screamed over him, waving his middle finger mere inches from his face.

To make matter worse, Aoki began to run around as he continued to give the crowd the bird.

"When I had his arm behind his back, I could feel it popping," Aoki said after the fight. "I thought, 'Well, this guy's pride just won't let him tap, will it?' So without hesitation, I broke it. I heard it break, and I thought, 'Ah, there, I just broke it.' I was stopped afterward, but even if I hadn't been, continuing to break it more would have been fine by me."

Feel the room Aoki, feel the room.

2. Paul Daly sucker-punches Josh Koshcheck

Photo Credit: © Mark J. Rebilas-USA TODAY Sports

"Josh Koscheck has never been hit like me."

Those were the words of Paul Daley before facing Koscheck at UFC 113 in 2010.

And while Koscheck was the one who came out victorious, Daley was able to land a clean shot on The Ultimate Fighter alum. Too bad it came with a price.

Seconds after their welterweight bout came to an end, a visibly frustrated Daley continued stalk Koscheck across the Octagon with a furious glare splashed across his eyes. As he drew closer to his opponent, Daley unloaded a vicious sucker-punch to Koscheck's smirking face.

Referee Dan Miragliotta immediately snatched up Daley and dragged him away while famously asking "Paul, are you kidding me? C'mon." A cageside Dana White could only gaze upon the scene, shaking his head in disgust.

"I don't give a s**t if he's the best 170-pounder in the world, he'll never come back here again -- he'll never come back," said White during the post-fight press conference.

And just like that, the once promising Daley was out on the street.

1. Rousimar Palhares

Oct 9, 2013; Barueri, Sao Paulo, Brazil; Rousimar Palhares reacts after defeating Mike Pierce (not pictured) during UFC Fight Night at Jose Correa Arena. Mandatory Credit: Jason Silva-USA TODAY Sports

Yes that's right, the single biggest showcase of unsportsmanlike conduct in MMA history can be boiled down to one man: Rousimar Palhares.

With the body of a He-Man action figure to go along with a bone crushing submission game, the Brazilian is truly a physical freak. As a former UFC veteran turned WSOF champion, Palhares should be one of the most sought-after free agents in the game

Too bad he got fired from almost every promotion he's ever fought in.

Palhares is notorious for holding submissions. Combine this with the fact his favorite submission move is the career-ending heel hook and it's safe to say Palhares is the one of, if not the most, disliked fighters on the planet. Don't believe me? Let's take a look at his résumé of craziness:

UFC 111 - Suspended 90 days for refusing to let go of a heel hook on Tomasz Drwal.

UFC on FX 6 - Suspended nine months after testing positive for elevated testosterone levels in his post-fight drug test.

UFC Fight Night 29 - Fired from the UFC for continuing to crank a heel hook on Mike Pierce even after the referee stepped in.

WSOF 16 - Questioned by WSOF officials for holding on to a kneebar too long against Jon Fitch.

WSOF 22 - Stripped of his welterweight title, fired from WSOF, and suspended two years for holding on to a kimura after the referee yelled at him to let go and gouging the eyes of Jake Shields repeatedly.

ADCC 2011 - Continued to crank a heel hook after referee stepped in, celebrated prematurely, warned for clubbing his opponent from within the clinch, and used an illegal method of breaking his opponent's submission hold.

So, there you have it folks. Either Palhares is actually the Brazilian Lex Luthor or he's a few tacos short of a combo plate. What's worse is he rarely shows remorse for his actions as he looks down on his opponent's mangled limbs.