Ditto's Mysterious Mansion - S1-E36
Continuity mistake: When Ash's Bulbasaur uses Razor Leaf, its nostrils disappear, while the inside of its eyes changes from white to black. (00:05:16)
Ditto's Mysterious Mansion - S1-E36
Continuity mistake: When Ditto, as a Bulbasaur, uses Vine Whip, it is briefly drawn with nostrils, even though it had not mastered changing its face at this point. (00:05:22)
Ditto's Mysterious Mansion - S1-E36
Continuity mistake: When Duplica goes over to her wardrobe to change into a Nurse Joy costume, the red brim of her Ash costume turns white. (00:06:02)
Ditto's Mysterious Mansion - S1-E36
Continuity mistake: When Duplica says that she will be taking her Ditto back from Team Rocket, the white trousers on Brock's disguise turn brown, like the trousers he usually wears. (00:15:53)