Supernatural, Super Spontaneous
Super Natural, one of the most popular television shows, featured a lead character with a big attitude, Dean. He was known for blurting out profanity every time he got mad or frustrated. So when he did the same in one of the episodes, no one thought anything of it. But little did the viewers know, Dean's dialogue wasn't scripted for that particular scene.
In reality, actor Jensen Ackles added his famous catchphrase into the scene at the last second, which surprised the writers and his co-star Jared Padalecki. Padalecki tried hard to hold back his laughter, but the surprise catchphrase worked so well that it made it into the final cut, leaving fans loving the moment.
