28. The Seinfeld Scare
Some actors prefer to stay in character between takes, making for an intense experience for the rest of the cast, especially if your character is a knife-wielding maniac like Elaine’s dad. Lawrence Tierney appeared in the episode “The Jacket” and gave everyone on set such a scare that co-creator Larry David jokingly threatened to bring Tierney back if the directors slacked. So what did he do?

In Seinfeld: Inside Look, the cast recalled Tierney walking around with a butcher knife tucked into his jacket, which he lifted from Jerry’s kitchen on the set. While everyone else steered clear of the sticky-fingered actor, Seinfeld casually confronted him, asking, “Hey Lawrence, what do you got there in your jacket?” Tierney responded by pulling out the knife and making stabbing motions toward Seinfeld while making Psycho sound effects.