I remember an interview with Ratzenberger a long time ago where he talked about his audition for Cheers. They asked what part he was auditioning for and he said “bar know it all.” He had their interest. There was some wood thing on the desk and he started describing it’s history as only Cliff could do. The show’s creators looked at each other as they had no such part in mind but after that, they made one.
Great story...never heard that before.