Character mistake: One of the other trainers said he rode over on a Pidgeotto, but it was a Pidgeot.
Continuity mistake: In Pikachu's vacation when Pikachu and the rest of his friends are pulling Charizard's head out, the rope that they use was not there during the previous shots.
Other mistake: Meowth calls one particular Pokémon in the test tube-thing a Sandshrew, however it is a Sandslash. This is a dubbing error, as Nyasu (Meowth's Japanese name) correctly identifies the Pokémon as a Sandopan (Sandslash's Japanese name) in the original Japanese version.
Audio problem: When Ash receives the letter from the Dragonite, we hear Togepi say "Togepi?" but its mouth doesn't move.
Other mistake: When the Poké Balls containing the Trainers' various Pokémon are sent to the DNA Cloning machine, Team Rocket incorrectly identifies Scyther as Alakazam. This is a dubbing error as, in the original Japanese version, the Rocket-dan (as they are called) correctly identify the Pokémon as a Strike (Scyther's Japanese name).
Other mistake: In Mewtwo Strikes Back, when the pirate trainer sends out Machamp (the four-armed Pokémon), the animation of it appearing is shown twice. Also, the sound effect that plays when a Pokémon appears isn't played the second time. There was a small section cut out of Ash throwing Squirtle's Poké Ball in the air. That was replaced with Machamp coming out twice.
Character mistake: As Team Rocket discovers the cloning machine made by Mewtwo, they start naming the shadows of each Pokemon as they appear on the screen. As the first Pokemon appears on screen, they say "Alakazam" but it is actually an outline of "Scyther" who is a different type of Pokemon.