Will Ferrell stopped by in the form of George W. Bush to wish Conan well on the eve of his last show as host of "Late Night." The former president smacked O'Brien on the ass and called Will Ferrell an "asshole."
Ferrell then stripped off his clothes to reveal a slutty leprechaun outfit and danced up on Conan for the last time on "Late Night."
Conan takes over the "Tonight Show" as of June 1. For a look back at Conan's run check out highlight's here.
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