Kōri no dōkutsu! (literally translated as The Ice Cave!) is the 250th episode of Pokémon, and was only released to in Japan. It was given a ban due to the fact that Jynx is shown with its original black skin. Seeing as this Pokémon's original skin tone was considered by some to be racist, the episode was banned.
Ash and friends enter the ice cave as it is a shortcut to Blackthorn City. After a watery run-in with Team Rocket, Brock catches a cold and the gang finds a Pokemon Center in the cave. While a Jynx working there is taking care of Brock, Nurse Joy tells Ash and Misty that the cave is cold because of a big building working there as a refridgerator. Team Rocket finds the building and they cause trouble by reversing the structure, heating the cave and cooling the jungle outside. Ash, Misty and Nurse Joy try to stop them, but they fall into a hole. After Team Rocket escapes to catch Ice-type Pokemon, Bayleef gets Ash, Misty and Nurse Joy out of the hole and then uses her vines to restore the pipe to its original place. Team Rocket arrives in front of the Pokemon Center and they manage to capture the ice Pokemon, including Jynx, by using heaters. Despite being in weakened state, Brock tries to stop Team Rocket, but they defeat him. Ash, Misty and Nurse Joy arrive just in time to help. Pikachu rescues the ice Pokemon by destroying the heaters. Jynx and the Piloswine use Blizzard to freeze Wobbuffet, Arbok and Victreebel, and then Pikachu sends Team Rocket blasting off with Thunderbolt. Now that Brock is feeling much better, Ash and friends leave the ice cave and arrive near the Blackthorn Lake.
This episode was mainly banned outside of Japan due to Jynx's racial stereotype appearance which appears to offend many people in the United States on whom are African-Americans. Because of this, the episode wasn't aired on 4Kids in Japan.