Description
Written and edited by Cohlman from @AandKGames
Animation Errors That Became Canon:
First off we have Derpy Hooves from My Little Pony: Friendship is Magic In the series premiere episode, a background pegasus pony was accidentally rendered cross-eyed due to a layout oversight by the animators. The internet immediately latched onto the character, affectionately naming her "Derpy Hooves" and since then the creators kept her wall-eyed expression as a permanent defining feature.
Speaking of series premiere errors, Family Guy’s series premiere ‘Death Has a Shadow’ show’s Peter’s eye unintentionally overlapping his nose. However, when Stewie and Brian travel back in time to this episode in Season 10, they just acknowledge it actually happening but nobody saying anything.
Then we have Waylon Smithers' Changing Skin Tone in The Simpsons. In his very first on-screen appearance in season 1, Smithers was mistakenly animated with black skin and blue hair. Decades later in the Season 31 episode "Screenless", Smithers directly references the coloring fluke by explaining it as nothing more than a horrible spray tan he suffered through during his early days at the nuclear plant.
And lastly we have Gumball's 3/4 Profile. This follows a common trope in cartoons of having certain characters avoiding a direct front viewing because of how uncanny it looks. After realizing Gumball needed to follow this, it became a critique made by Darwin.