A Dairy Tale Ending (Japanese: ミルタンク！リベンジバトル！！Miltank! Revenge Battle!!) is the 159th episode of the Pokémon anime. It was first broadcast in Japan on August 10, 2000 and in the United States on August 18, 2001.
Whitney takes our heroes to her uncle's Miltank farm in the outskirts of Goldenrod City. Here they sample the finest in Miltank dairy products and learn how to groom and care for these Pokémon. Ash realizes this is a great opportunity to study Miltank first-hand and hopes it will help him against Whitney's Miltank in their next battle. After learning about Miltank and coming out victorious in a battle against Team Rocket, Ash realizes the answer to overcoming Whitney's strongest Pokémon is good old-fashioned team-work.
After Ash's Pokémon recover, Whitney takes the group to spend a day at her uncle's dairy. Later, Jessie, James, and Meowth attempt to raid the pantry for all of the dairy produce they can find, but they are discovered by Whitney and forced to flee. Ash gives chase, and Pikachu attacks the trio, causing them to drop the stolen food. Jessie and James send out Arbok and Weezing, and Whitney sends out Miltank. Miltank hits the trio with a Rollout and sends them flying. Later, the group is brushing the farm's Miltank, but the one Ash is brushing decides to walk away. Ash grabs its tail, and it responds by kicking him into a fence. Afterwards, Milton shows the group the milking machine.
As Whitney is practicing her Miltank's Rollout, Ash recalls how it made short work of his Pokémon in their earlier Gymbattle. Whitney's training is cut short, however, by Team Rocket, who return in a giant rolling barrel. They recite their motto and use arms that sprout from the ends of the barrel to grab Miltank and Pikachu. Ash turns to face the barrel and sends out Cyndaquil, which uses Tackle, stopping the barrel's advance. Ash then uses Totodile's Water Gun to carve trenches in the hill. They cause the barrel to bounce and shake so violently that James snaps the control levers, dropping Miltank and Pikachu. Pikachu launches a Thunder Shock, which causes the barrel to explode, sending Team Rocket flying again.
Ash and Whitney agree to have another battle, with Cyndaquil, Totodile, and Pikachu facing off against Miltank. Ash starts with Cyndaquil, but it is quickly defeated by Miltank's Rollout. Next, Ash uses Totodile, and again has it use Water Gun to dig trenches in the ground. Totodile then launches itself into the air with another Water Gun, and lands on top of Miltank. However, Whitney orders Miltank to shake it off, and she does before hitting it with Rollout. Ash returns the defeated Totodile to its Poké Ball before it even hits the ground. Finally, Ash sends out Pikachu, and orders him to use Agility. Pikachu's speed causes Miltank to hit some of the trenches in her attempts to attack. As Miltank comes round for another attack, Pikachu positions himself in the bottom of one of the trenches. As Miltank rolls over the top, Pikachu tosses her into the air. Pikachu then uses Thunder Shock on the airborne Miltank and wins the match.
Whitney offers Ash the Plain Badge, much to his surprise, since it was not an official Gym battle. However, she and Milton convince him that beating a Gym Leader's top Pokémon fair and square is what counts, and he accepts it.