Ash originally obtained it as a Krabby in Mystery at the Lighthouse, where he caught it to prove to Misty that it was not a fluke that he captured all his other Pokémon. Having six Pokémon already in his party at the time, the newly caught Krabby's Poké Ball was teleported away, much to Ash's surprise and concern. He soon learned that Krabby was sent to Professor Oak.
Krabby's battling debut came in Round One - Begin!, when Ash used it during the first round of the Pokémon League against Mandi, reasoning that Krabby would be perfect for a battle on the Water field despite Misty's protests that Ash should borrow one of her Pokémon as Krabby had never battled before. Despite this, Krabby was able to defeat Mandi's Exeggutor, the intensity of the battle causing it to evolve into a Kingler. It was able to finish the rest of the match by defeating Mandi's two remaining Pokémon, Seadra and Golbat, despite Misty and Brock's concerns about Kingler's ability to prevail against Seadra's speed and Golbat's air attacks. Ash also used Kingler in his battle on the Ice field -although he may have used Kingler on the Rock field, this was never shown-, where Kingler defeated Pete Pebbleman's Cloyster before losing to a surprisingly powerful Arcanine.
Kingler spent most of the time at Oak's lab as Ash and his friends traveled the Orange Islands and the Johto region.
Ash used it in Johto during the Whirl Cup tournament in The Perfect Match. It was used in the match against Misty and her Poliwhirl and Psyduck.
Ash was planning to use Kingler in the Johto League Silver Conference, but it was injured while rescuing a group of runaway Voltorb making it unable to participate in the rest of the tournament.
In Showdown at the Oak Corral, Kingler made a cameo appearance telling the other Pokémon about Cassidy and Butch.
Kingler currently resides at Professor Oak's Lab, where it quickly made friends with Ash's Corphish in The Right Place and the Right Mime.
