Modern Family
When Mitch and Cam adopted a baby on Modern Family, it made sense that they'd need a new kid for the next season. Babies grow fast, so it wasn't long before the twins who played Lilly, Ella & Jaden Hiller, were too old for the part. They were replaced by Aubrey Anderson-Emmons, who grew up on the screen. She stayed in the role from toddlerhood all the way to her teenage years.
Two and a Half Men
Who was surprised to see Charlie Sheen go off the show? When the famous actor went off the rails on live TV, his career went with it. He lost a lot of respect in Hollywood, but he also lost his marbles and lost his job on the show Two and a Half Men. The show didn't last much longer after his removal, but Ashton Kutcher was brought into the unvierse for the ending seasons. Talk about an upgrade!