As one of the most dangerous sports, it shouldn't come as a shock to many that MMA fighters are crazy.
Just getting into the ring is reason alone to question one's sanity.
Taking blows to the head and pounding an opponent into unconsciousness.
From fighting techniques to legal troubles, some of the world's best fighters fuel their aggression to higher levels.
As leagues such as the UFC increase in popularity and Pay Per View continues to dish out events, mixed-martial arts becomes more relevant to pop culture.
Here are the 10-most "bat-crazy" MMA fighters around.
Jesse Taylor goes down as the only fighter to ever be removed from a final due to events that occurred after filming was completed of SpikeTV's "The Ultimate Fighter 7."
UFC President Dana White was given a security recording that showed Taylor kicking out one of the side windows of a rented limousine.
Hotel staff also reported that a drunken Taylor had frightened female patrons and confronted hotel security by acting aggressively and screaming.
Taylor's actions kept him out of the final match with White saying that the fighter didn't possess the mental discipline to handle the pressure and popularity of the UFC.
But White later brought him back when Taylor decided to go to Alcoholics Anonymous meetings.
Last month, however, the UFC let him go allegedly based on several factors that ranged from talking trash about the league to lying about attending AA meetings.
UFC play-by-play announcer Mike Goldberg once said, "this man is not human."
Wesley "Cabbage" Correira is best known for his "strong chin," which allows him to sustain blows to the head without being knocked out.
Perfect examples can be found against Tim Sylvia at UFC 39 and Andrei Arlovski at UFC 47.
Adding to the man, the myth, the legend, Correira absorbed the highest number of power strikes ever.
As he once said, his head is full of "concrete and stuff."
Quinton "Rampage" Jackson decided to take the role of Sergeant "B.A." Baracus in a remake of "The A-Team" and UFC 107 was postponed because of it.
The iconic badass character, originally played by Mr. T, was a no-win for Jackson.
That's why he gets "bat-crazy" points for delaying his battle with Rashad Evans.
Not even one-line zingers and hot celebrities like Bradley Cooper and Jessica Biel could save him.
After signing with the World Fighting Alliance in 2006, Rampage went back to school at Baylor University, but flunked when he didn't attend classes.
Rampage was also involved in a hit-and-run incident and a high-speed police pursuit in Newport Beach, Calif. He pleaded guilty to the charges.
Nicknamed the "Axe Murderer" for his aggressive style, Wanderlei Silva earns the majority of his victories by knockout or referee stoppage.
In Brazil, they have a Portuguese nickname for him: "Cachorro Louco," or the "Mad Dog".
He lost a match in 1997 because of a cut above his left eyelid that opened up several times. Despite this, Silva would use the cut side of his head for butts on Artur Mariano.
Silva missed action for most of this year when he underwent facial surgery to repair his nose and remove scar tissue just above his eyes.
All the better to avoid bleeding and being easily cut open during future fights.
As the WEC Featherweight Champion, José Aldo stands at 17-1 in his career.
The recipient of the 2009 Fighter of the Year, Aldo has been making a name for himself as a striker with six of his seven WEC fights by knockout or technical knockout.
At the age of 17, he fought his first professional MMA fight and defeated Mário Bigola by knockout with a head-kick just 18 seconds into the first round.
For Bigola, it would be his first and only professional fight.
Aldo also fought Hudson Rocha in 2004 and it was called by doctor stoppage at the end of the first round due to a cut over Rocha's left eye.
It was caused by a flying knee thrown by Aldo, which was followed by a supply of punches. Though Rocha was able to get back to his feet, Aldo met him with more punches and a knee before kicking his legs out from under him.
His "go-for-the-kill" mentality makes Aldo one of the "bat-crazy" MMA fighters.
Tito Ortiz can't seem to shake off the aggressiveness even when he leaves the ring.
In 1998, he was sentenced to jail after pleading guilty to charges of "battery with serious bodily injury" in Orange County, Calif. Ortiz was sentenced to three years probation, 29 days in jail, and 232 hours of community service.
But that wasn't the end of his troubles away from MMA.
Ortiz was arrested on April 26 for suspicion of domestic violence at his and Jenna Jameson's home. She could be seen with "visible injuries."
The couple, though not married, lives a monogamous relationship and has twin sons born in 2009.
Local authorities later chose not to pursue the case, citing a lack of collaboration from the witness.
All this is fitting for a guy nicknamed the "Huntington Beach Bad Boy."
During post-fight interviews between Jake Shields and Dan Henderson in April at Strikeforce: Nashville, Jason "Mayhem" Miller interrupted Shields after being invited into the cage.
"Where's my rematch, buddy?"
A brawl took place as soon as Shields and Gilbert Melendez pushed him away. Members of the Cesar Gracie Jiu-Jitsu camp attacked Miller and he had to be restrained on the canvas.
Miller and five others were given three-month suspensions and fines of $5,000-$7,500.
He also earned a no-decision when he landed a soccer kick, something that isn't allowed in Dream fights.
After another fight, a riot broke out and Miller was punched in the back of the head by a fellow fighter.
A rematch took place and Miller finished the opposing fighter with an armbar at the end of round one—making the famous shaka (greeting) sign before finishing him.
Before Brock Lesnar's MMA days, he was an NCAA champion in wrestling with the Minnesota Golden Gophers.
In his earlier years as the undisputed WWE champion, he formed feuds with the Undertaker, the Rock, and Hollywood Hulk Hogan.
During a match, he suffered a concussion on a botched move—slamming his head into Kurt Angle's side and ribcage. Lesnar also broke Hardcore Holly's neck in 2002.
When his time with the WWE ended, he decided to give the NFL a try with the Minnesota Vikings. In some preseason games, he started minor fights.
After his win at UFC 100 in 2009, Lesnar flipped off the booing crowd and insulted Pay-Per-View's primary sponsor, Bud Light, claiming it "won't pay me nothin'."
Later on he would apologize when he took everything a step further and said he might even "get on top of [his] wife."
Lesnar completes the intimidating look with a stylized skull in the center of his back and a large sword on his chest.
Lee "Lightning" Murray can now be found in a Moroccan slammer.
In June, he was sentenced to 10 years in jail for masterminding a 2006 £53-million burglary in Kent. Moroccan police also charged him with possession of hard drugs.
Last year, he tried to escape from prison by starving himself and sneaking small saws to cut the prison cell bars.
Murray's UFC record concluded at 1-0 since his US visa was revoked because of the ongoing investigation.
He was allegedly involved in a 2002 scuffle with then-UFC light heavyweight champion Tito Ortiz outside of a nightclub in London.
Murray also was hospitalized in 2005 after being stabbed in a brawl outside the Funky Buddha club in London.
Jarrod Wyatt might want to lay off mushroom tea in the future.
In March, he and his sparring partner Taylor Powell drank the psychedelic drug and then became obsessed with the idea of an impending end to the world. Apparently, they were convinced that there would be a final struggle between God and the devil.
What came next is graphic.
Wyatt allegedly ripped out Powell's heart, cut off his tongue and face, and all the while Powell was alive.
A California judge upheld the murder charges as well as charges of aggravated mayhem and torture.
Wyatt would go on to admit that he cooked the body parts in a wooden stove to "stop the devil."