I went looking for this last night, found it relatively easily, and watched it for the first time in a good two decades. When it was over I had to stifle the urge to applaud.
John Moschitta Jr. was spotted on an episode of That's Incredible! and hired to portray Mr. Spleen (yes, they gave him a name) for Federal Express. He's in the Guinness Book of World Records for talking 586 words per minute.
Watch his eyes; dead and unblinking, they're almost funnier than his speaking. And speaking of speaking, let's have a shout-out for Mr. "Well sir I think on my feet I'm good with figures and I have a sharp mind" at :07-:08.