On Olden Pond (Japanese: ハクリューの湖！Hakuryu's Lake!) is the 152nd episode of the Advanced Generation series, and the 426th episode of the Pokémon anime. It was first broadcast in Japan on November 17, 2005 and in the United States on September 30, 2006.
Ash and his friends visit a famous fishing spot that looks oddly abandoned. Ash still manages to hook a Crawdaunt, which he challenges with Corphish. But Crawdaunt wins and begins wrecking property until a woman named Tiffany chases it off. Tiffany explains that the lake was busy until a year ago, when Saridakis Industries wanted to fill in the lake and turn it into a spa. Tiffany wouldn't sell out, but Crawdaunt scared off all the fishermen and Pokémon.
Naturally, Ash and friends help her out. They track down Crawdaunt, which belongs to Mr. Saridakis himself! Team Rocket is there too, disguised as consultants so they can steal Crawdaunt. Tiffany confronts Saridakis, who says he didn't ask Crawdaunt to ruin the lake. But he'll battle Ash and Corphish tomorrow: if Saridakis wins, he gets the lake! He fell into the lake once when he was a boy and though he somehow survived, he's hated the place ever since.
To help Ash train for the battle, Tiffany's Granny Galea challenges him with her Vaporeon. By cleverly using the terrain, her Vaporeon is able to beat Corphish. The next day, Ash also has Corphish use the lake to its advantage while battling Crawdaunt. Except Team Rocket interrupts the match and steals Crawdaunt!
Ash and his friends stop them and rescue Crawdaunt, but in the commotion, Saridakis falls into the water. He's saved by none other than Granny and a Dragonair, who saved him back when he a boy, too. Saridakis realizes it'd be wrong to fill in the lake, and things return to the peaceful way they were as Ash continues towards his Battle Frontier destination.
Looking on his PokéNav, Max suggests they rest up at a nearby famous fishing spot. Arriving at the lake, everyone is surprised by the area’s eerie silence and absolute desertion. At the local boathouse, Max finds some fishing rods and equipment. Ash and Brock start fishing in the lake waiting for a while until something attaches onto Ash's line. Unable to control the sheer power of the Pokémon at the end of the line, May, Max, and Brock jump to help Ash pull and lose control. Pulling with all their might, everyone falls back and releases a Crawdaunt from its watery chamber. Recovering from the fall, May quickly looks up Crawdaunt's Pokédex data. Crawdaunt is as ferocious as ever as Ash quickly sends out Corphish. With Corphish being the pre-evolution of Crawdaunt, it appears that Corphish could be the weaker counterpart. Both Pokémon attack with their Vice Grips colliding, but Crawdaunt easily overpowers Corphish and knocks it backwards. Now unleashing dual Crabhammers, Corphish is easily overwhelmed. Crawdaunt follows up with a Bubble Beam, and despite Corphish using a counter Bubble Beam it is knocked to the ground. Crawdaunt grabs the fishing poles and breaks them in half with its pincers.
Tiffany arrives on the scene, sending the Crawdaunt fleeing back into the lake. Brock is instantly enchanted by Tiffany’s beauty, though Max pulls him away. Ash apologizes for the broken rods, though Tiffany is glad to see some passing trade. She explains that in the past when the lake flourished with both Pokémon and customers. Though the prime fishing spot was also of interest to Mr. Saridakis of Saridakis Industries, who hoped to turn the lake into a luxury spa resort. Tiffany refused to sell the boathouse to him. A Crawdaunt appeared shortly after, frightening all the Pokémon and customers away from the lake.
Now with a revived ambition, everyone starts out in search for the Crawdaunt. With Squirtle, Corphish and Marshtomp dive into the lake, Brock and Ash join Tiffany in a boat while May and Max search the lake’s edge on foot. Tiffany spots the Crawdaunt heading into a cave as Brock slows the boat. After following Crawdaunt, it is discovered that the Crawdaunt is not wild, and that its Trainer is Mr. Saridakis. Team Rocket pose as architects, conspiring to build Saridakis' Leisure Land vision while sponging off of the developer for food. Tiffany confronts Saridakis with questions, though he doesn’t offer any insight. Ash steps forward and challenges Crawdaunt to a battle. At this, Saridakis suggests that they make the match tomorrow, and if he wins he will get the lake and boathouse, though he will abandon his plans if he loses. Saridakis is set on fixing the lake for good, namely because he says it’s dirty. He explains that he was pulled into the lake while fishing as a child, nearly drowning in the process. He later woke up to find himself safely on the shore, though no one was around. He reiterates that his development plans will rectify his childhood trauma and be a nice cash boost. Abruptly ending the story, he walks off with a laugh.
Returning to the boathouse, Ash has Corphish take on Pikachu in a practice match. Tiffany’s grandmother, Galea admits that Ash will never win with his current tactics. She calls out her Vaporeon for a demonstration and challenges Ash to a match. Corphish begins the battle off with a Crabhammer, but Vaporeon quickly dodges the slow attack. Now out in the lake, Corphish goes for another Crabhammer attack though Vaporeon seemingly blends into its surrounds using Acid Armor. As Corphish searches for its opponent, Vaporeon appears from behind and lands a Quick Attack on it. Corphish is knocked back and finds itself tangled amongst the water grass. Corphish is then defeated by Vaporeon's overpowering Hydro Pump. Galea explains to Ash that a Trainer must adapt to the situation by using the surroundings as an advantage.
The day of the arranged match has arrived. Mr. Saridakis and Ash are about to battle, with Corphish beginning with a Crabhammer. Crawdaunt responds with its own Crabhammer, but this time when the attacks collide, Crawdaunt doesn't overpower Corphish. Corphish then launches a barrage of Bubble Beam, though Crawdaunt’s own Bubble Beam proves more powerful forcing Corphish to make a swift evasion. Crawdaunt goes for a Vice Grip attack as Corphish quickly dives underneath the water. Corphish emerges from behind and strike Crawdaunt with a direct Crabhammer. Crawdaunt goes for another attack just as Corphish Hardens its body blocking Crawdaunt's attack. Corphish then retaliates with a devastating Crabhammer knocking Crawdaunt into some nearby rocks.
Barely able to move, Crawdaunt is snatched by Team Rocket's new mecha. Following their motto, the trio snatch Pikachu as well before speeding off into the distance. While Saridakis gives chase in his own vessel, Tiffany orders the group into her boat as their Water Pokémon lead an assault on Team Rocket. Though Meowth evades the airborne attacks with ease. In response, Corphish lifts Squirtle and launches it towards the mecha. Squirtle withdraws into its shell and begins rotating at high speed, colliding into the mecha with a Rapid Spin, though it fails to knock the trio off course. Marshtomp saves Squirtle from the fall with Water Gun. Corphish then launches another Bubble Beam attack increasing Squirtle's Rapid Spin once again towards the mecha. The attack makes a direct hit with this time damaging the mecha's engine, forcing Team Rocket to begin their descent towards the lake, where a collision blasts them off.
A gigantic wave created by the explosion washes everyone, except Saridakis, ashore. The lake’s rumored Dragonair and Galea rush to rescue Saridakis from the depths. He then realizes that Dragonair was the same Pokémon that saved him from his childhood drowning. Saridakis watches as Galea and Dragonair effortlessly bring him to the shore. Saridakis is confused by the rescue effort, though Galea admits that she loves the lake too much to allow anyone to drown. Saridakis then goes to thank Dragonair as it begins its descent into the lake once more. In a surprising change of heart, Saridakis shelves his Leisure Land development plans as he would be harming Dragonair. Tiffany is relieved by the news. Suddenly Dragonair's cry echoes through the surrounding area, purifying the water to a picturesque blue and the nearby Water Pokémon begin to return to the lake.
Based on the cover art of Pokémon Mystery Dungeon: Blue Rescue Team
Based on the cover art of Pokémon Mystery Dungeon: Red Rescue Team
During the battle, Ash has Corphish dive underwater to dodge Vice Grip. Less than a second later, Crawdaunt lands on exactly the same spot where Corphish was able to be completely submerged and the water only comes up a few inches, thus having Crawdaunt stand on water.