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, Misty and Brock continue their journey to Blackthorn City. They decide to take a short cut through the Ice Cave.
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.