While the show and games come under the same banner, intertwined with each other through the same world, they have entirely different aspects to each. Not the least of this is certain Pokémon's power levels, with some examples doing complete 180's by the time they reach the small screen.
It's either some of the legends of the series being taken down surprisingly easy or a few learner Pokémon pulling it out of the bag against heavy hitters. In the show, there seems to be a lot more variation in power level through the species, making predictions in battle almost impossible to do. At the end of the day, there's no drama without a little unpredictability.
10 Kingler
Kingler's anime journey has a very stop and start road, initially being one of the smallest and most mocked Pokémon in his roster. It wasn't even on his team, being kept with Professor Oak for safekeeping. It was only when the League battles started up that it started beating late game Pokémon and evolving on its first battle.
For what it's worth, Kingler isn't a terrible Pokémon in the game, but it certainly doesn't live up to the standards set by the show. Though it's attack and defences are high, it has a very low HP with a sub-par special defence. Making it incredibly vulnerable to the attacks it falls weak against.
9 Heracross
Heracross started out with its own ups and downs in battle, falling victim to a Donphan in its early days with Ash. It then went on to prevail in some significant battles, before being transported to Professor Oaks for his own personal study.
It was even used against Gary in Ash's Silver Conference fight and overcame a type disadvantage to get a win over a Magmar. If only it were so impressive in the game, falling short due to its vulnerable type matching and abysmal special attack.
8 Pikachu
Being the star of the show gives the fan favourite a considerable boost in power, being able to take down Pokémon that are far out of its league power-wise. All kinds of type disadvantage and clear power imbalance can't take this Pikachu down, the benefits of being a fan favourite.
In the game, however, any kind of plot armour or dramatic effect goes out the window. Leaving the Electric mouse exposed to the big bad world of powerful attacks, ones that his rock bottom defence can't live up to.
7 Infernape
This is a case of setting the bar far too high for yourself, or the Pikachu effect as it's called in some circles. It also suffers from having a good backstory in the anime, setting it up to outperform its physical limits in the show.
While a capable member of any team and one of the most offensive starters in the entire series, Infernape is a favourite for those that can dull out damage quickly without having to take the heavy hits. Its weaknesses make it a prime target for some of the heavier attacks from over half of the types available.
6 Bellsprout
This may be one of the biggest disparities between the two mediums, making one of the weakest and generally novice Pokémon into a battle threat. Being able to defeat both Bulbasaur and Pikachu when Ash battled against it the first time, even besting Team Rocket at the end.
In the games, Bellsprout has some of the worst stats in the game. Essentially serving as a beginner grass type that can get players through the first half an hour of the game. It's only when it evolves that the chlorophyll filled Pokémon can do any significant damage.
5 Kadabra
Being a psychic Pokémon in the first generation was a blessing, being the most powerful type in the series up until that point. Kadabra was the main Pokémon on Sabrina's team, a team that presented one of the biggest challenges to Ash in Kanto.
It's HP, attack and defence stats are some of the lowest in the whole series, the only thing that stands out is it's high special attack and speed that sets it up for devastating moves. It isn't terrible so much as it is a roller-coaster ride of up and down statistics.
4 Sceptile
The only Pokémon in the series to defeat a legendary, Sceptile holds the title for the most accomplished in the anime. Especially seeing as it's the only one period to take out Darkrai, despite being hit by some of its heaviest attacks. Even taking on a second legendary in Latios despite losing that battle.
In the game, the starter has a respectable offence with some great stats when it eventually evolves into the fully realized Sceptile. Taking on the legendaries is a different story, in fact it isn't even the best starter in its generation, making the legend far supersede its actual ability.
3 Gardevoir
One of the strong Pokémon that falls to the wayside, Gardevoir has sneakily been rising up the power rankings for years. Now finally being put to display in its Gigantamax form, the psychic type is starting to pick up some steam in the community.
It has one of the best type combinations in the game accompanied by some of the highest special attack. That's right about where the trail runs dry, with very modest stats for the rest of the graph, Gardevoir's hype train might have jumped the shark a little when it comes to actual combat.
2 Dragonite
From its dramatic debut in the first season, Dragonite has cast a large shadow since the first time fans laid eyes upon it. Though its role is usually not combative, when it does show up to fight it has some of the most impressive performances to date.
While Dragonite is an iconic character in the series as a whole, the dominant battle role it plays in the show makes the game version look sad. Once fans are past the first few generations more and more Pokémon start to show up who can take the almighty dragon down.
1 Beedrill
Though we don't see Beedrill in combat much throughout the show, characters seem to be constantly running away from them. Showing some pretty incredible speed and attack power for being one of the first Pokémon Ash meets, it seems swarms cause major havoc in the show.
Unlike the anime, Beedrill is only a pest in the Viridian Forest. Even then it's one of the best Pokémon you can catch on that route. Realistically, the lowest level Charmander can take out 10's of Beedrill at a time, making the supposed fear completely unfounded.