Water-type Pokémon are arguably the most common within the Pokémon universe and this is mostly likely because, similar to the real world, a large portion of the region is actually made up of water.

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With more than 20 seasons of the Pokémon anime, over 20 movies, and 8 generations of Pokémon, Ash has encountered a lot of Water Pokémon on his adventures, be they wild Legendary creatures, fighters belonging to a rival, or allies of Ash himself. As Water is always a typing for a starterPokémon, it is no surprise that he has owned several, but it's another thing entirely to train them and turn them into formidable battlers.

10 Clair's Kingdra Could Have Beaten Ash If Not For Interference

Kingdra Pokemon

Despite arguably being more of a threat in the games than in the anime, Clair’s Kingdra still caused Ash a number of problems. Its moveset of Twister, Hydro Pump, Agility, Hyper Beam, and Swift gives it considerable firepower while also enabling it to dictate the pace of a battle.

It resisted Pikachu’s attacks and nearly knocked Noctowl out before Clair had to stop the bout when Team Rocket interfered by stealing the Dragon Fang. Ash was ultimately somewhat fortunate, as he was able to defeat Kingdra with his Snorlax in the rematch, after having time to re-think his strategy.

9 Piplup And Empoleon Were Loyal Battlers

Empoleon in a battle stance in the Pokémon anime

In Pokémon Diamond & Pearl, Piplup is Dawn’s trusted companion. Despite being relatively weak towards the start, in terms of battling, Piplup gradually becomes much stronger and capable at battling.

Its fully evolved form, Empoleon is seen several times throughout the Pokémon anime, most notable with Barry in Diamond & Pearl and Professor Kukui in Sun & Moon when he faces off against Ash at the end of the Alolan Pokémon League. In both cases, Empoleon’s power is showcased but is exposed by its weaknesses, losing to Pikachu and Melmetal respectively.

8 Katie's Walrein Turned The Tide Of Battle But Was Fooled By Ash's Strategy

Walrein Katie Pokemon

In the Hoenn Pokémon League, Ash comes up against a very tactical Katie. After a very close battle it comes down to her Walrein versus Ash’s last three Pokémon. Walrein makes perfect use of the water on the battlefield, moving quickly for its size and knocking out Swellow with an Ice Beam and Corphish wish a devastating Body Slam.

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It has Grovyle’s number too until it inadvertently freezes the battlefield due to a well-thought-out strategy by Ash, giving it less room to maneuver and it ultimately gets defeated by Grovyle.

7 Buizel Loved A Challenge And Became One Of Ash's Best Teammates

Buizel Ready For Battle in Pokemon

In Sinnoh, Buizel initially belongs to Dawn before she realizes that it would rather battle than participate in contests, so she trades for Ash’s Aipom. In ‘A Crasher Course in Power!’ Buizel faces off against the Pastoria Gym Leader Crasher Wake’s Floatzel, the evolved form of Buizel, eventually overpowering its evolution counterpart following some tactical switches by Ash.

Buizel is very strong and its Swift Swim ability makes it a formidable battler, even to the point that Ash never needs to evolve it. Against Fantina of Hearthome City, Buizel spins and uses Water Gun creating a Counter Shield for Gengar’s Hypnosis.

6 Milotic Was Strong But Could Not Defeat Pikachu

Anime Pokemon Pikachu Versus Lucy's Milotic Battle

Milotic would arguably have caused Ash more problems in the anime if he didn’t have Pikachu. Ash’s two main battles against the majestic serpentine Pokémon, against Sootopolis Gym Leader Juan and Battle Frontier member Lucy, see Milotic defeat one of his Pokémon, Swellow, and Donphan respectively, before falling to Pikachu.

Wallace and Lusamine also owning this Pokémon perfectly represents its grace but also its power as one of the best Water-types a trainer can hope to use.

5 Suicune Had Other Priorities But Could Also Be A Tricky Battler

Goh's Suicune in Pokemon anime

As one of the Legendary Beasts of the Johto region, Suicune is not seen too often in the anime, but when it does show up, it is normally fleeting and not in a battle. However, in ‘For Ho-Oh the Bells Toll!’, Suicune is forced to attack Team Rocket when they cause chaos in Ecruteak. Suicune also engages Eusine in battle, albeit using defensive moves like Mirror Coat and Roar, before fleeing the area.

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It has demonstrated its kind nature on multiple occasions, saving Nurse Joy’s daughters Marnie and Page in ‘Drifloon on the Wind!’ and purifying water in Celebi: The Voice of the Forest.

4 Squirtle Was A Loyal Friend To Ash And Blastoise Was A Powerhouse

Blastoise charges forward

Ash’s Squirtle is well known for being one of his most useful and loyal Pokémon, especially throughout the Kanto adventures. Its strength in character is on show from the moment Ash and friends meet it as a part of the Squirtle Squad.

Its evolved form Blastoise has been used a lot in battles by various trainers, most notably Gary Oak and Tierno. Siebold, a member of the Kalos Elite Four, handed Alain and his Mega-Charizard a rare defeat at the hands of his Mega-Blastoise, solidifying him further as one of the strongest trainers in Kalos.

3 Kyogre Was Pure Destruction When Disturbed

Kyogre Leaping

Even though Kyogre is under Archie’s control when it debuted in ‘Gaining Groudon’ in the Ruby and Sapphire series, it still certainly shows its power and destructive capabilities, when it faces Pikachu, Groudon, and Lance’s Gyarados. This is exactly how an ancient Legendary is likely to react especially when it's being manipulated.

In Pokémon XY, Primal Kyogre and Primal Groudon awoke, with Primal Kyogre attacking anyone who would make a move against it, once more showing its destructive prowess.

2 Gyarados Would Always Put Up A Good Fight

Gyarados

In the anime, every time a Gyarados is encountered in the wild or in a battle, its intimidating stature and aggressive nature are there for all to see. James of Team Rocket technically owned a Gyarados briefly, but because James kicked it as a Magikarp, it evolved immediately and attacked the evil trio with Dragon Rage.

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Misty is seen Mega-evolving her Gyarados against Ash’s Pikachu in ‘When Regions Collide!’ and Lance Dynamaxes his Red Gyarados when facing Leon and his Gigantimax Charizard in ‘Flash of the Titans’ during Pokémon Journeys.

1 Greninja Was Ash's Not-So-Secret Weapon

Ash's Greninja bonded with him

While Ash wins many matches with his Froakie and Frogadier, the final evolution Greninja is when Ash really started to gain momentum. Ash’s Greninja has the ability Battle Bond, which allows it to change into a formidable version of itself, Ash-Greninja, which also allows Ash and Greninja to share each other’s pain and exhaustion.

Ash-Greninja proceeds to give Diantha’s Mega-Gardevoir and Alain’s Mega-Charizard close battles with great intensity despite not winning outright, but it does defeat Wulfric’s Mega-Abomasnow to get Ash his final Kalos Badge.

NEXT: Pokémon: Every Generation, Ranked By Their Pokédex