Looks can be deceiving, and that holds very true in the Pokemon world, especially among gym leaders. Just because a gym leader looks like they'd be strong or weak doesn't mean they are. There are some gym leaders that look like they'd be very strong but are actually pushovers, but the reverse can be true as well.
Some of the most cutesy and innocent-looking gym leaders are actually the toughest in the entire series, proving that it doesn't matter what the trainer looks like — it's how they work in tandem with their Pokemon. Don't be fooled by the appearance of a gym leader — some of the weakest-looking can take you down before you have a chance to stop them.
10 Iris
Players making their way through the Unova region in Generation V will face a different gym leader as their eighth challenge depending on which version they have. Those with Pokemon Black will face off against Drayden in Opelucid City, while those with White will have to take on Iris.
Just looking at these two, one might assume that Drayden is way harder than Iris. But, don't get it twisted. Iris is no easy pushover — her Dragon-type team is just as brutal as Drayden's, and Iris is so powerful that she goes on to become the League Champion in the sequels.
9 Ramos
Some gym leaders seem like they're just holding the position as a side hobby from their regular lives. Ramos is definitely one of these types. This elderly man loves gardening, focusing on it for the most part, and always carrying around his trusty garden shears.
An in-game television show even talks about how Ramos has gotten really into cultivating tea lately. He seems like just a nice older guy who has retired to his gardening.
However, in his spare time, Ramos busies himself with taking down hopeful trainers by using his Grass-type Pokemon in the Coumarine Gym. He's not the most difficult challenge in Kalos, but he's tough and his Gogoat definitely packs a punch.
8 Tate and Liza
Children in powerful positions is a staple of the Pokemon series, from the protagonists being preteens and taking down evil organized crime gangs to serving the post of gym leader in a few cities. One example of this is Tate & Liza, twins who head up the Mossdeep City gym in Hoenn.
These two are literal children, and may seem like pushovers. However, they consistently find themselves on rankings of the hardest gym leaders in the series, and many fans have struggled significantly to take them on successfully.
7 Whitney
Whitney is one of the best examples of a total surprise when it comes to a Pokemon game. Her appearance and behavior both suggest she's a sensitive, pink, cutesy sprite of a person. Her gym is pink and full of flowers, Whitney herself is just a small, timid young woman, and her Pokemon are all cute and pink.
However, Whitney is a powerhouse trainer. She's given more trainers trouble than maybe any other gym leader in the series, and her Miltank strikes fear into the hearts of grown adults everywhere. Watch out for this one.
6 Elesa
While Whitney is a bit of a crybaby throwing a fit when she loses, Elesa is another type of woman: confident, even arrogant, poised, and self-assured. She's a model who is rather concerned with her appearance, which may lead some to think she's a bit of the stereotypical airhead.
But, Elesa is quite the opposite. She's a driven trainer with a powerful team of Pokemon, withstanding some of the best players who challenge her. She's also the one who stands up to Bianca's father, and she joins with the other leaders to take down Team Plasma.
5 Opal
Like Ramos, one might think Opal is just an elderly woman. Everything about her suggests she's frail and weak. She walks with great effort, uses a cane, and is well up there in years, resulting in her hunched and fragile appearance.
However, Opal can tussle with the best of them. Her Fairy-types are cute, but they'll be smacking down your strongest Pokemon before you know it. She's successfully held on to her post as Ballonlea's gym leader for 70 years, and she even came within reaching distance of the League Championship a few decades before the events of the games.
4 Lenora
As only the second gym leader in the Unova region and a specialist in Normal-type Pokemon, Lenora doesn't really seem like she'd be that difficult. She also has the appearance of a gentle and kind mother, which suggests she wouldn't be a fierce opponent.
However, those who were fooled by these characteristics were in for a rude awakening. Lenora is tough — some even say the most difficult fight in Unova. Her Watchog and Herdier are stronger than you'd expect, and they've given a lot of trouble to many players.
3 Candice
Johto, Sinnoh, and Unova all feature Ice-type specialists as the second-last gym battle, and Kalos has an Ice-type user as the final gym. It seems the type is used by those who are meant to be some of the most difficult challenges in their respective leagues.
Candice, the Ice-type leader in Sinnoh, definitely lives up to this characterization. She's an extremely tough fight, hitting hard and taking no prisoners. Many players have struggled to take her down, with all of this being comical given the fact that she's a literal child with pigtails and a sweater tied around her waist. Get 'em, Candice.
2 Wattson
Have you ever seen one of those chill dads that likes to barbeque in his sandals and be a big loveable oaf turn into a scary aggressive man when he has to? Wattson is kind of like that. Normally, he just appears to be a big, jolly guy, having a laugh and just joking around telling dad jokes.
But, he's a force to be reckoned with in battle. His team in Emerald is slightly better than in Ruby & Sapphire, but in both, he is a tough leader to take down. There exists some debate over who is harder — Tate and Liza or Wattson — but the point stands that he is much scarier than his appearance would suggest.
1 Jasmine
Jasmine, leader of the Olivine City Gym, may not be the most challenging fight on this list, but she is much tougher than her appearance (or even personality) would suggest. If someone had never played one of the Johto games, they might look at Jasmine with her little bows, frilly dress, and love of helping sick Pokemon and think she specializes in the Fairy-type.
But, Jasmine doesn't joke around with weak defensive types. She specializes in intimidating and powerful Steel-types. Jasmine's ace is even the gigantic and terrifying Steelix. She used to specialize in Rock-types, but that apparently wasn't good enough, and she took it to the next level.