In today’s day and age, sports stars come in all shapes and sizes and hail from all different backgrounds. Of course, you still have the typical person’s view of what an “athlete” is, like a big football player or a tall basketball player. But in recent years, with speed and finesse having a much bigger impact in almost all major sports, smaller and quicker athletes have become superstars. The way how an athlete looks has also changed over the years.

Since the prototypical “athlete” as we know it has changed in recent years, so should our views and perceptions on how athletes should look. We have to get used to the idea that athletes can be smaller, skinnier, younger etc… than we were used to in the past. This new influx of different types of star athletes has led some of the public to discredit athletes simply based on the way they look, the way the act or how they present themselves.

One thing that your parents probably told you as a child is to never judge a book by its cover and that is exactly what this article will focus on. This article will look at 15 unsuspecting athletes who could kill you if they wanted to. If you were walking down the street and had no idea who these athletes were, you wouldn't move over them or be wary of them in the slightest. The athletes here range from small, feisty basketball players to seemingly overweight to 115 pound women who can likely beat up 99% of the population.

Whoever they are and whatever they do, these are 15 athletes that you do NOT want to mess with!

15 15. Nate Robinson

Nate Robinson is an NBA guard who has played for a variety of teams and found success with most of them. Robinson measures in at a miniscule 5’9 and yet still has a reputation as one of the toughest players in the league. On top of that, he definitely has a hot temper. If you saw him in regular street clothes, you likely wouldn’t think much of him at all, but in reality, this is guy who has participated in numerous fights throughout his career, always with men much bigger than him and who will never back down from anyone.

14 14. Holly Holm

Outside of the world of combat sports like boxing, kickboxing and MMA, few people would know who Holly Holm is, but they absolutely should. Holly Holm is a fairly physically imposing woman at 5’8 and 135 pounds, but is also a good looking girl, which could fool some folks into thinking she is harmless. However, that is not the case, as Holm was 33-2-3 as a pro boxer and is currently 9-0 in her MMA career. Holm has been successful in everything that she has ever tried and could without a doubt kill you if she wanted to.

13 13. James Johnson

James Johnson is an NBA forward who currently plays for the Toronto Raptors and is arguably the toughest man in the NBA. Despite him being a relative unknown to most casual fans and not a very intimidating looking individual, Johnson could likely beat up anyone in the NBA and likely a large majority of the people on this planet. This is because he not only holds a second degree black belt and has competed in MMA, but he also holds an undefeated record in kickboxing matches at a staggering 20-0!

12 12. Mario Balotelli

Mario Balotelli is a striker who currently plays for Liverpool, though he's out of favor there, which has been the norm for his career. He is a fairly lanky man and doesn't offer a lot in terms of real intimidation, but still finds himself on this list. He does not appear on this list because of any kind of previous background in fighting or martial arts, but he appears on it because he's prone to insane behavior. Super Mario has been in trouble for a laundry list of things including throwing darts at a youth football team. He may not be a great fighter, but sometimes being fearless and crazy is more than enough.

11 11. Paige VanZant

Paige VanZant has recently burst onto the scene in UFC circles as the new “hot” face of the female 115 pound Strawweight division. VanZant emerged last year and already has impressed fans around the world with her model good looks and her great performances in the cage. The 21 year old star with the “girl next door” looks also has recently been awarded with an exclusive Reebok sponsorship, making her one of only a few to be awarded with such a deal. Though she looks barely older than a high schooler, she could without a doubt kill you if she felt like it.

10 10. David Akers

The last player on an NFL team that you might fear would likely be the kicker. However, in the case of current free agent kicker David Akers, you would be sadly mistaken. This is because Akers has been training in various martial arts such as Shaolin Kempo and jiu jitsu for just shy of ten years now, which makes him more than capable of kicking your ass. Also, Akers has obtained a blue belt in jiu jitsu, which makes him capable of taking you out with a wide array of chokes and holds.

9 9. Tom Zbikowski

Though he is not currently in the NFL right now, Tom Zbikowski is probably the toughest and best fighter to have ever been in the league. Now this may come as a shock to some as Zbikowski is only 5'11 and 200 pounds, but there is little doubt when you become aware of his pedigree. Zbikowski has been a professional boxer since 2006 and has amassed a pro record of 4-0 with three wins coming by way of knockout. Despite his short stature and size for an athlete (especially in the NFL), he is the last guy you would want to mess with.

8 8. Miesha Tate

Miesha Tate has been a contender in the female 135 pound division in both Strikeforce and the UFC for the last five years. She is a very well rounded fighter and is a handful for any woman, or man for that matter, on the planet. What makes Tate even more unsuspecting than most individuals is that she is an absolutely beautiful woman and normally when people think about professional fighters, they don’t often think of them having model good looks as well. If you tried to pick her up and she didn't care for your advances, it's likely that she could fold you into a pretzel and throw you out of the bar.

7 7. Theo Fleury

Theo Fleury is a former star player in the NHL and also known as one of the toughest men to ever lace up a pair of skates, which most people would find extremely surprising due to his historically small stature. Despite standing at a miniscule 5'6 and weighing only 180 pounds, Fleury was not afraid of anyone, no matter their size. He played an extremely physical style of hockey that led to numerous altercations, which Fleury never ever shied away from, despite being one of his generation's smallest players.

6 6. Steve Blake

Now this one is going to shock some people, but it's absolutely true. Steve Blake is an NBA point guard who was just traded to the Detroit Pistons and might be one of the last players in the NBA that most people would think is a fighter. Blake has not only been training with MMA fighters for years, but he is also not afraid to shy away from bigger men. On the court, Blake plays a very chippy game and has been in his fair share of altercations with men much bigger than he is, but he has never backed down from any of them.

5 5. Tie Domi

If you are an NHL fan and think of legendary fighters in league history, one name that will surely arise is that of the former Maple Leafs enforcer, Tie Domi. For people who aren't fans of hockey, they'd simply see a man who stands at a miniscule 5'8 and is not that intimidating, but they would be incredibly wrong in their assertion of Domi. Domi regularly fought and beat men MUCH bigger than he was and actually holds the record for the most penalty minutes in Maple Leafs history. Just ask the Flyers fan who chirped him in the penalty box if Domi is a man to be messed with..

4 4. Demetrious Johnson

Our number one entry, as people unfamiliar with Demetrious Johnson would never suspect this man to be able to beat them up. “Mighty Mouse” is the current UFC Flyweight Champion and is in the conversation for the best pound for pound fighter in the world. Standing at only 5’3 with a subdued demeanor, Johnson is a far cry from you would expect from a cage fighting champion. In fact, those who don’t know the fight game wouldn’t even look twice at this guy, but if they tested him, they'd regret it.

3 3. Phil Mickelson

When people see Phil Mickelson out on the links playing golf, they see a man in his mid 40s who looks slightly out of shape and not intimidating at all. However, he is a perfect example of why you should never judge a book by its cover. This is because Mickelson has been training Kung Fu and Taekwondo for years and can likely beat you up because of it. He first took up martial arts in 2001 when he hired a trainer who is a martial arts expert and turned Mickelson on to martial arts.

2 2. Floyd Mayweather

Boxing fans know all about the skills possessed by Floyd Mayweather, but uniformed people who would see him walking down  the street would not be privy to this information, though we're aware that it's nearly impossible to be unaware of him at this point. Mayweather, who stands at 5'8 and has movie star/actor good looks, hardly looks like a world class boxer, but that is exactly what he is. In fact, many would argue that Floyd Mayweather is actually pound for pound the best boxer of all time. We are inclined to agree as he has amassed a flawless pro record of 48-0.

1 1. Ronda Rousey

Coming in at number one is none other than the biggest star in the UFC today, the undefeated Women’s Bantamweight champion, Ronda Rousey. Nowadays, most people who pay attention to sports know about her, but MMA fans have known of her brilliance for years. Despite being a very attractive woman with a bright and vibrant personality, this girl is the most dangerous on the planet. Rousey is undefeated in MMA, is a former Olympic Judo star and is now one of the biggest stars in sports. Her signature arm bar is one of the most deadly moves inside the octagon.

Now, we're aware that everyone knows who she is right now, but let's pretend this is a parallel universe where she's as talented, but not widely known. If you saw her walking down the street, would you be aware that she could break every bone in your body with ease? Probably not.