The Legend of Dratini ban

During the broadcasting days of mh:besttvshows:Pokémon: Indigo League (from 1997-1999 in Japan; 1998-1999 in the US and Canada), the thirty fifth episode of Season 1 (in Japan and China) titled "The Legend of Dratini" was banned from airing outside of Japan by 4Kids Entertainment due to the pervasive use of firearms, which are pointed at Ash and Kaiser and were also fired at Jessie, James, and Meowth. Even though the scenes where Kaiser threatens Ash, Misty and Brock with his guns were intended for comic effect, 4Kids Entertainment still found this too dark for children. This caused major confusion for long time fans and even newcomer fans to the point there was a considerate plot hole in the first season's international dubs that didn't explain how Ash captured his own flock of Tauros.

The episode was also banned in South Korea due to references of Japanese culture due to Japan and South Korea having a rocky relationship, and has not been unbanned in South Korea ever since, even after the relationships between the two countries warmed up.

Banning
This controversial episode was banned in almost all countries outside of Japan (including the United States), largely due to the pervasive use of firearms, which are pointed at Ash, and Kaiser also fired at Jessie, James, and Meowth. Even though the scenes where Kaiser threatens Ash, Misty and Brock with his guns were intended for comic effect, 4Kids Entertainment still found this too dark for children. 4Kids used footage of this episode in the Pokérap, which means that they obtained the episode from Japan. However, according to Eric Stuart, there was never an English dub for this episode, as network television refused to have it aired when the scene with Kaiser pointing a gun at Ash was shown. Unfortunately for fans, when the episode was skipped, it created a major plot hole for non-Japanese versions of the show, confusing many viewers on how, when, where, and why Ash caught thirty Tauros, although Professor Oak mentioned it once in "Showdown at the Po-ké Corral". To a lesser extent, the episode also explained Team Rocket's plan for "Ditto's Mysterious Mansion".

Some sources also claim that Meowth's moustache during the interrogation scene resembles that of Adolf Hitler and thus contributed to the banning. However, it is more likely that this moustache is based on a stereotypical detective moustache instead.

On a related note, this was technically the fourth banned episode to feature a fairly important event, as "Challenge of the Samurai", "Pokémon Scent-sation!", and "The Ninja Poké-Showdown", which featured Ash's Metapod's evolution into Butterfree, Ash earning the Rainbow Badge, and Ash earning the Soul Badge, respectively, had been banned in South Korea due to overt references to Japanese culture because of tense relationships between the two countries (specifically, samurais, Japanese traditional clothing for women, and ninjas, respectively).

Why This Ban Sucks
'Note: This is not directly against the episode at any cost. This is pointing out why this banning against said episode is quite simply terrible.'
 * 1) Instead of editing out the guns (or coloring them) into something a gun can do, the episode itself is banned by 4Kids and other countries outside of Japan altogether. No clear editing for foreign countries to see, no English translation dubbing, just a pure ban and that is it. Which is one of the worst things they have ever done when it comes to the days of when Pokémon was dubbed by 4Kids.
 * 2) Because this episode got banned from every other country outside of Asia (mostly Japan), fans (either longtime fans or newcomer fans) would be confused as heck wondering where Ash's Tauros came from.
 * 3) This ban is completely hypocritical because 4Kids could ban the episode for the use of firearms and gun shootings. Yet they dubbed the episodes of the same season where guns were shown and exposed.
 * 4) * "Here Comes the Squirtle Squad" has one scene where Team Rocket was holding up a shop with ice guns holding a seller hostage. And another from where Ash is taken hostage by the police before Mrs. Jenny shouts out that "he is not from Team Rocket".
 * 5) * "Tentacool and Tentacruel" was banned for a period of time from 2001 - 2005 from television after the events of 9/11 and Hurricane Katrina, but was not banned again because of one scene where Nastina has a gun trying to shoot down the Tentacruel.
 * 6) The banning of the episode in South Korea is also not any better. Get this: As said above, the episode is banned in South Korea because of the references to Japanese culture. Although this makes sense because back then Japan and South Korea had tense relationships in the past, but that doesn't mean South Korea's ban against the episode is any better.

Redeeming Qualities

 * 1) "The Legend of Dratini" itself is still a good episode, it's the ban on the episode and the plot hole is what is wrong with the English/international dubs of the anime.
 * 2) Although it's hypocritical of 4Kids to ban the episode worldwide. At least they showed some of the footage from the episode showing the footage of a Dratini, Dragonair, and a Ryhorn used in the original Pokérap music video, as well as a clip of Ash, Misty, and Brock catching a Gyarados. The footage with the Dragonair and Dratini was also used in the Pikachu's Jukebox music video, "What Kind of Pokémon Are You?".
 * 3) * As also stated above, the events of Ash catching his Tauros were mentioned for continuity in the English dub of "Showdown in the Poké Corral" by Professor Oak instead of forgetting about them for no reason entirely, despite making a plot hole anyway.