Chadwick Boseman seemed born to play Black Panther, but in fact, he auditioned for a much quirkier Marvel movie before that film was even in the making.
Mattel and WB execs worried Greta Gerwig's Barbie might be a little too inspired by Todd Haynes' dark take on the toy with Superstar: The Karen Carpenter Story.
The creatives behind Star Wars Rebels were determined to get the series finale just right, which led to them retooling the big showdown between Zeb and Rukh.
Michael Dorn changed his acting to account for Worf's decision involving his brother Kurn in the Star Trek: The Next Generation episode 'Sins of the Father.'