History Main / RetCon

** Simba's and Nala's cub at the end of the first scene has male markings, but is technically [[AmbiguousGender never called a male]]. The sequel redesigns the cub to look female and made her into Kiara. [[WhatCouldHaveBeen Originally]] there were going to be twins, which would explain the unknown female cub while keeping the original male cub, but Kiara's twin brother was scrapped to fit continuity and because writing multiple cubs wasn't working well.
*** The much later ''WesternAnimation/TheLionGuard'' series split the difference by giving Kiara a younger brother, Kion. The final season contrives a reason to have Kion and his friends out of the way and off screen during the time ''WesternAnimation/TheLionKingIISimbasPride'' takes place.

* The ''Franchise/{{Saw}}'' franchise became infamous for this after the [[OnlyTheCreatorDoesItRight new writers came aboard after the third film]] (which was supposed to be the last one), as they completely changed the direction of the tone and story, creating new characters that apparently existed that we didn't see or hear about in the previous films (FBI being in contact with Detective Kerry), things like Hoffman helping Jigsaw from the very beginning, and character traits that weren't really implied (Rigg suddenly having an obsession to save people, etc...). In contrast, the two previous films had retcons that were believable because there were obvious connections that were made clear.