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)
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)