Other mistake: During the Pokérap, when the Poliwrath name is said, the Pokémon shown is actually Poliwag. Also, when the Graveler name is said, the Pokémon shown is actually Geodude.
Other mistake: Larvitar's weight is 158.7lb, but Ash can carry it in his backpack without any problems.
Pokemon, I Choose You! - S1-E1
Other mistake: When Ash gets Pikachu's Poké Ball from Professor Oak, the latter's hand right hand is drawn backwards. (00:06:52)
Pokemon, I Choose You! - S1-E1
Other mistake: When Pidgey turns its head to see Ash with a Poké Ball, its head feathers beside its eyes are mistakenly coloured cream instead of brown. (00:11:36)
Other mistake: When Nurse Joy says, "Transporting Poké Balls," the screen changes between shots. Also, the land and water have their colours reversed with the cities appearing on water instead of land. (00:14:45)
Other mistake: When the computer in the storage room says, "Downloader activated," the land and water are reversed with the cities appearing on water instead of land. (00:15:02)
Clefairy and the Moon Stone - S1-E6
Other mistake: When the camera begins panning back to show Seymour, Ash, Butterfree, Zubat, and Brock, Pikachu's mouth is missing. (00:11:18)
The Path to the Pokemon League - S1-E8
Other mistake: When A.J. is grateful when Sandshrew returns, his Butterfree's antennae are missing occasionally. (00:15:24)
Bulbasaur and the Hidden Village - S1-E10
Other mistake: In the scene when Team Rocket tries to steal the Pokemon, Bulbasaur saves Oddish. Ash comes to help push Bulbasaur, and for a few frames you can see 2 sets of hand prints cut out where Ash's hands go.
Mystery at the Lighthouse - S1-E13
Other mistake: When Ash and friends are first seen walking on a path, Pikachu's cheek pouches are missing. (00:01:14)
Mystery at the Lighthouse - S1-E13
Other mistake: When Professor Oak goes to rotate his monitor, his right index finger is intermittently not coloured in. (00:09:15)
Mystery at the Lighthouse - S1-E13
Other mistake: When the front of the Kabuto costume falls off, the part of Bill's body above his arms is missing. (00:12:34)
Mystery at the Lighthouse - S1-E13
Other mistake: When Brock turns his head to the costume, his nose is missing. (00:12:47)
Suggested correction: Agree with the other correction. Dropping details, such as facial features like a nose or mouth, and simplifying character designs is a very common and encouraged drawing/animation technique to imply distance. This isn't something the animators would just overlook. It was a deliberate decision. Ash and Misty similarly look somewhat less detailed than they do in closer shots. At best, this would be a deliberate mistake, but I personally think it falls under the umbrella of "suspension of disbelief" and shouldn't be considered a mistake given it's a stylistic choice to imply distance.
Suggested correction: His nose isn't seen because he is far away from the camera.
Mystery at the Lighthouse - S1-E13
Other mistake: When Bill says, "A meaning for all Pokémon, and a meaning all of us humans too," a Sandslash on a screen has an entirely yellow head and has black pupils with white sclerae. Sandslash actually have the lower part of their head coloured cream and have their white pupils with black sclerae. (00:14:01)
Electric Shock Showdown - S1-E14
Other mistake: When Ash mentions that Lt. Surge must be a great Trainer, a Rattata's left eye is missing. (00:02:43)
Battle Aboard the St. Anne - S1-E15
Other mistake: When showing Raticate and Butterfree on a screen during the first trade, they are coming from the sides that their Poké Balls are not on. (00:11:58)
Other mistake: When Ash, Misty, and Brock are worried about the cyclone approaching, the edges of Meowth's ears are mistakenly colored tan instead of black. (00:20:08)
Island of the Giant Pokemon - S1-E17
Other mistake: In the recap, when Ash, Misty, and Brock are worried about the cyclone approaching, the edges of Meowth's ears are mistakenly colored tan instead of black. (00:01:16)
Island of the Giant Pokemon - S1-E17
Other mistake: When Ash wakes up on the beach, part of the sides of the hat overlaps the front. (00:01:53)
Island of the Giant Pokemon - S1-E17
Other mistake: When Jessie says she cannot stand roller coasters, part of the background is coloured in like her hair. (00:17:26)
