Butterfield Ate...

...BUtterfield 8-3000.  It's  Johny Carson Carnac joke, explained here:

"The ironic connection is the telephone number of New York‘s funeral home to the stars, Frank E. Campbell. For years the funeral directors that laid the likes of Judy Garland and Rudolph Valentino to rest used to advertise: ―In the event of death call BUtterfield 8-3000."