Just saw an early episode where Mel plays a cab driver--I still remember him from a guest spot on The Beverly Hillbillies where he also played a cab driver who took Granny home and wound up thinking they were all residents of a mental institution. He described Jethro as having a "few bubbles in the think tank."
In the Jack Benny episode I referenced, Mel, as a cab driver, claimed to be an old high school classmate of Jack's from Waukegon, and asked Jack, "What are you doing these days?"
After a pause (of course), Jack responds, "I'm the voice of Bugs Bunny" and both men broke out in laughter.
Si! Sigh! Sue!
Have seen that routine many times and lose control every time!!
And not a vulgar word anywhere!