I loved Mitch Hedberg's one random appearance on That 70s Show.
"I did not lose a leg in Vietnam to serve hotdogs to teenagers."
"But Frank, you have both your legs."
"Like I said, I did not lose a leg in Vietnam."
I never watched that show on a regular basis but I can recall this episode. Mitch Hedberg is an amazing comedian too. I've been watching a lot of his stuff on Youtube lately and that dude had talent.