It takes a unique mindset to be a professional athlete. To go through regular agony of your body, the pressures of the team, handling press, public and more. To know that folks who have never played the game are judging you as “experts” and ready to tear you apart for the smallest mistakes. To be judged for accomplishments before you even make your debut. It’s a lot to take and no surprise so many guys can crack. They can act up, go wild and more, the sports world is littered with such cases.

Now what about folks who are a little…off to begin with? If success and fame can transform rational people into wild folk, what about the type who are already nuts? In some cases, it can be truly wild behavior, mostly for fun, guys blowing off steam in unique ways. In others, it can be dangerous and show some truly troubled individuals. Plus, some guys may be okay in playing days but then lose it afterward. It’s a tricky thing balancing “eccentric” with truly nuts but some guys really do cross that line big time. Here’s a list of 20 athletes whose antics, behavior and more can earn them spots as the craziest to ever take a field.

By the way, this really goes for just pure professional athletes as if you counted pro wrestlers, you’d need to expand this list massively and there’s more than enough nuttiness in the sports world to go around. Also, while tempting to count coaches like Bobby Knight, keeping this to just on play athletes as that’s a whole other list to go with.

20 20. Joe Don Looney

If ever a man was appropriately named, it was Looney. While he made All-American at Oklahoma, he was kicked off the team for punching an assistant coach and a terrible student. Recruited to the NFL, he spent his six-year career with five different teams, each one soon sick of his antics. He hated practices, openly saying “if practice makes perfect and perfection is impossible, why bother practicing?” He made one of the more famous moments in NFL history when his coach wanted him to carry a play to the quarterback and Looney made the immortal reply “you want a messanger boy, call Western Union.” After retiring, he converted to a radical Hindu sect that made him an enforcer. He was in trouble with the law before dying in a motorcycle accident in 1988, a fitting end for a wild man.

19 19. Sean Avery

Trash talking is nothing new in sports and hockey players are good at it. But Avery took it to a new level…a rather low one, many agree. It’s one thing to take a shot on a guy but he mocked a player over his leukemia, created what is now called “the Avery Rule” by waving his stick in front of Martin Brodeur, argued with fans and openly told reporters that other hockey players dating his exes, Elisha Cuthbert and Rachel Hunter, were them taking “my sloppy seconds” which got him massive condemnation and a suspension. That’s on top of his wild play with smashing into opponents and starting fights. True, the guy has argued for marriage equality among other stuff but that seems a bit off for someone who seemed to enjoy raking on others as much as Avery has.

18 18. John Daly

You don’t think of golfers as really party animals and/or wild folks. John Daly is an exception to that rule. The fact he named his clothing line “Loud Mouth” should tell you that. While he has some major wins to his credit, Daly is known for his short temper and often wild play that just increased as time went on. He was disqualified from the 2002 Australian Open for throwing his putter into a pond and refusing to sign his score card. He later broke a spectator’s camera and another time hit every one of his balls into the water. He’s had issues with alcohol but didn’t make himself popular speaking in a 1994 interview of so many fellow golfers on drugs themselves. He’s cleaned up a bit but still one of the wilder figures golf has known and a standout among sports' wild men.

17 17. Frenchy Bordagaray

At a time when ballplayers were always clean shaven, Frenchy stood out with his gorgeous mustache. A good player, he was soon well known for his goofball ways such as when Casey Stengel protested him being caught out at second base but Bordagaray piped up that he had been caught between taps of the foot. Another famous moment was when Frenchy was caught out and Stengel yelled at him about not sliding. So when he hit a home run, Frenchy slid into every base and when he came home, Stengel yelled about fining him $50 “for showing me up!” Always with an eye to playing on his fame, Bordagaray was funny in a time when baseball was a bit stricter and showmanship was a good time.

16 16. Rob Gronkowski

The New England star is well regarded as a key part of the Patriots' dominance the last few years. He’s also famous for being one of the wildest guys in the NFL today. The man revels in his rep from buying a party bus to showing up for children hospitals dressed as a Christmas tree, hooking up with adult film star Bibi Jones and acting like a little kid running around at the ESPY Awards. While much of the Patriots team are held in high regard as champs, Gronk shows that there are some funny guys around and it’s hard to hate someone who obviously enjoys what he does and is along for a great ride.

15 15. Larry Eisenhauer

When you’re nicknamed “Wildman,” you should back it up. And Eisenhauer did it big time as the Patriots defensive end was well known for his brutal play with hard tackles but the bigger damage often seemed to himself. His warm-up routine included smashing his head and/or arms into lockers and walls and a famous moment where he ran onto a snowy Kansas City field in only his helmet and jock support. There’s also the famous moment where he jumped naked into what he thought was a regular hotel swimming pool only to discover it was the underwater tank for a “mermaid show” in front of hundreds of guests. Then there was when a local TV show wanted a clown character to “try out” for the Patriots only for Eisenhauer to maul the poor guy for real. A favorite among Patriots, a true wild man for the ages.

14 14. Luis Suarez

A new children’s book has the Liverpool striker featured as a vampire. Many will see that as more than appropriate for a guy whose play on the field could be wild and bloodthirsty. We see soccer plays punch and such all the time but Suarez has been flagged for biting no less than three opponents, most recently in the 2014 World Cup and has been known for racially abusing others players. The man is an incredible talent to be sure but it says a lot that when facing him, opponents have to worry more about the use of his teeth than his feet.

13 13. Bill Romanowski

Yes, he is a fantastic player with four Super Bowl rings to his credit. But let’s never forget Romanowski is also one of the wildest guys on or off the field ever. This is a man who spat in an opposing quarterback’s face during a PRE-season game. Who ended the career of his own teammate, Marcus Williams, by punching him in the eye during training camp so hard it cracked Williams’ orbital socket. Who gave his autobiography the title: “My Life On the Edge-----Living Dreams and Slaying Dragons.” Even as an NFL analyst, he’s prone to some wild tangents and baffling declarations of everything from sex life to the dangers of bacon. A true nut but best not to say so to his face if you value your own.

12 12. John McEnroe

It’s not like tennis was a stranger to high-strung players (no pun intended). But John McEnroe changed that persona forever with his combative nature. While he was amazing with Grand Slam titles, most people watched less for his play and more to see him blow his top. It seemed the slightest thing could set McEnroe off as he would berate umpires over foul calls and seeing him slam his racket or toss it around was a common sight. Today, he’s the first to poke fun at that image in commercials and TV shows but it just highlights how the supposedly quiet game of tennis could get pretty damn rowdy whenever McEnroe took to the court and a temper that’s still talked of in legendary tones today.

11 11. Mike Danton

Battles between athletes and their agents are as old as the business. But it rarely leads to attempted murder. That’s just what happened in 2004 when Danton, a star for the St. Louis Blues, contacted what he thought was a professional hitman to kill his agent, David Frost. The “hitman” was actually a police dispatcher and Danton was arrested and phone calls between him and Frost hinted at a homosexual relationship between the duo, adding more craziness to this. Then Frost was put on trial for supposedly exploiting minors. You think that’s enough? It turns out Danton’s attorney never actually graduated law school and he ended up going to jail himself. Danton is out today and still trying to play hockey and one has to wonder how it must be going against a guy willing to literally kill amid all these other antics.

10 10. Lefty Gomez

On the one hand, he was one of the greatest pitchers in Yankees history, a seven-time All-Star who sparked the team to four straight World Series championships in the late 1930s. But Gomez was also known as one of the most colorful characters in baseball, a man who once struck a match inside the batter’s box to “aid” the umpire in seeing the ball right. He once stopped a World Series game just to watch an airplane fly overhead and would occasionally shake up teammates by tossing the ball to them rather than make a play “just to see how they react.” While manager Joe McCarthy would go crazy over Lefty’s antics, the man backed it up with top-notch play and showed how a clown can get things right if he tries.

9 9. Diego Maradona

Where do you start? His interviews where he was obviously coked out of his mind, firing a rifle at reporters, kicking Athletic Bilbao and using his hand to score a goal against England at the 1986 World Cup and claiming it was revenge for the Falklands War. That’s not to mention the massive brawls he triggered, his wicked play with attacks on opponents and his later disastrous run as a coach where he fought more with his own team than helped them win. There is no denying the man is one of the best soccer players ever but is far more infamous for also being one of its all-time biggest nuts.

8 8. Gilles Gratton

When you design your goalie mask to be your astrological sign, you’re automatically up for a spot on this list. But that was just the beginning of the various antics of “Gratton the Loony” as he would hiss and growl at opponents on the ice. He claimed the nickname “the Count” as he had been a Spanish lord in a previous life and also believed he had once been an executioner who stoned people to death and thus being a goalie was “punishment” for his actions then. Another famous incident was refusing to play a game because the moon wasn’t lined up properly with Jupiter. That’s not even mentioning fights, streaking and how he could play classical piano despite never having taken a lesson. While talented, he quit hockey at 24 and was last heard somewhere in Europe, no doubt living even crazier than ever.

7 7. Ron Artest

First off, the man is known today as Metta World Peace. He legally changed his name to that. If that doesn’t speak volumes to how nuts he is, I don’t know what does. In his rookie season he applied for a job at Circuit City just to get an employee discount…after signing a multi-million dollar contract. There’s also how he was involved in the ugliest brawl in NBA history, right in the middle charging into the stands to attack a fan which landed him the longest suspension ever. Sure, he had a career afterward and even a NBA Championship ring with the Lakers but this is a man who prided himself on “being ghetto” from wild interviews to smashing TV cameras and promoting rap albums. The name may change but that legacy will remain insane no matter what.

6 6. Mike Tyson

Once, Mike Tyson truly was the most feared man on the planet. He was a force of nature mauling opponents left and right and seemed unstoppable. But by the mid-1990s, Tyson’s quirky behavior had become dangerous, his intensity now turned to excessively wild behavior that led to his imprisonment. It got worse when he made his comeback and climaxed in the now-infamous bout with Evander Holyfield where Tyson bit off part of Holyfield’s ear, a segment that was ludicrous by anyone’s standards. He’s mellowed a bit and played into his wild past but one look at the tattoo covering half his face or allowing himself to be turned into a literal cartoon character reminds you that Tyson is a guy who let his mental issues overwhelm his boxing fame.

5 5. Viacheslav Datsik

Even by the standards of Russians and/or MMA fighters, Datsik is, quite frankly, a complete raving lunatic. In the octagon, his fighting “style” looks like glitches from a video game, lots of jerky motions, leading with his head in charges and frenetic shots that he somehow thinks will work. But his antics outside the arena have led to his fame from his wild videos to being arrested and claiming Jesus Christ was a Mossad agent while Datsik himself was the son of a Slavic god. He then escaped the prison hospital by tearing the fence with his bare hands and upon being arrested, claimed he wanted the maximum sentence to live a healthier life as he’s “too raw for humanity.” Whatever happens next, the man has shown that getting wild is something that crosses borders.

4 4. Dennis Rodman

Rodman has talent, no one can deny that. You don’t win five NBA championship rings and be a seven-time rebounding champion by just pure luck. But his off-court antics have gotten him far more attention than his playing ever did. It started with just the changing hair color but grew from that from his involvement in pro wrestling to promoting his autobiography in a wedding dress. It’s gotten wilder as he’s left the game with his antics including several arrests, Twitter rants and of course his journey to North Korea to get along with its dictator leader. It’s a shame as the man was a damn good player but it’s his bizarre behavior that’s made him more of a name these days.

3 3. Evel Knievel

Did you really think we’d get through this list without him? Even by the standards of daredevils, Knievel was something especially nuts. It was there when his early biking led him to plunge his town into a blackout and carried to rodeos, where facing wild bulls was seen as a calming thing for him. That soon led to his legendary jumps like Caesar’s Place, Snake River and so many more. Half of these ended in crashes that shattered nearly half of Evel’s body at one point or another in his life but he’d just get back and try again, even talking of a Grand Canyon jump one day. He was a huge star in his time, even in movies and in his aging days, still talked of doing one more big stunt. That a man would keep going at the same thing that nearly killed him time and again shows a streak of insanity that made Evel such an icon for many.

2 2. Tim Rossovich

There’s some nutty behavior…and then there’s Tim Rossovich. The man’s penchant for pranks went from just wild fun to absolute insanity that would make “Animal House” look normal. During his days at USC, he would indulge in stuff from smashing bottles across the dorm hallways to filling the elevators with water so they splashed onto waiting visitors like a Three Stooges flick. Despite all that, he was a great player who helped USC to a championship and was soon picked for the NFL…where he got wilder.

Among his antics; leaping buck naked onto a birthday cake at a party, showing up at a door lit completely on fire, yelling to opponents “I love you man, but I gotta take you out!” and wearing a fake plaster cast before smashing it in a bar. On the field, he attacked opposing players and practice sleds with equal fervor and while injuries kept him from rising higher in the NFL, he was still a good player for his decade. Most importantly, Rossovich was just out for the pure fun of things and one of the biggest nuts pro sports has ever seen.

1 1. John McNally aka Johnny Blood

The NFL’s original swashbuckler, McNally took his nickname from a Rudolph Valentino movie and more than lived up to that spirit. He was as wild off the field as on it and would have been banned from playing if not for the fact his fantastic skill helped drive the Green Bay Packers to four NFL titles. A famous moment is when coach Curly Lambeau refused to give him an advance to go drinking so Blood did the logical thing. He climbed out of his hotel room, crossed the ledge of an eight story building (in a rainstorm no less) and hopped across a chasm to get to the hotel room of a stunned Lambeau who gladly gave up the money if Blood promised never to do such a stunt again.

That was just one of Blood’s many wild adventures. Escaping a fight by crawling onto the top of a train and riding the roof to the destination, playing an entire game with a collapsed kidney, doing chin-ups on the flagpole of an ocean liner…while it was in the middle of the ocean, missing a train due to partying so driving his car onto the tracks to block it so he could get on board…as he was the coach. After retiring, he enlisted in the Army for WWII and as a coach in various universities, set a bar for wild behavior. Just goes to show how the “golden age” was as full of nuts as today.