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When Homer asked the Yes Guy why he spoke like he did, the Yes Guy responded, “I had a stro-o-oke!”. He is often seen working at Costington's department store, and is apparently on good terms with Mr. Costington. When Lisa was put on trial for teaching fellow students about Darwin, the Yes Guy was juror number twelve. He also once worked as an ice cream truck driver and gave Bart some free ice cream. Apu considers the Yes Guy to be very, very funny.
Yes Guy also once worked for the reality show Frame Up, where he pretended to take a phone call from the governor regarding whether a condemned Homer should be reprieved. During the call, he used his catchphrase (and a "No" version of it) several times.
His name is revealed to be "Mr. Pettigrew".
 Behind the Laughter
The Yes Guy is a tribute to character actor Frank Nelson, and his familiar persona on The Jack Benny Program (modified for appearances on I Love Lucy, The Flintstones, Sanford and Son, and others). Nelson's trademark greeting was a loud, drawn-out “Yeeeeesss?!” This was often augmented with a sarcastic "OoOOOoooh!" Originally, this character could be found in a variety of occupations, usually as a salesman or waiter, at establishments which Jack Benny or others might be patronizing, and his Simpsonian counterpart is equally omnipresent.