Regis Philbin dressed up as Shrek for a surprise appearance on Letterman Tuesday night. He spent 2.5 hours in makeup to come out after the first guest Beyonce to promote "Regis and Kelly's" Broadway week.
Dave cut him off with a "who cares" a few words into his plug."Why bother," Philbin sighed before walking off, and it was over in two minutes. WATCH: