Mike Moffitt is a friend of Cosmo Kramer's who calls Jerry Seinfeld a "phony" and fights with George Costanza over the "dream spot" in front of Jerry's apartment in the episode "The Parking Space". Jerry later confronts him about this, and Mike then pretends that he meant "phony" as slang for "cool", the way "bad" can actually mean "good".
Mike appears again in "The Susie", where he thinks Jerry wants to get rid of him after his thumbs are accidentally broken by Jerry's car trunk and he gets trapped inside of it. He then misinterprets Jerry and Elaine's conversation, thinking Jerry murdered Elaine's imaginary colleague Susie. He therefore bursts into her memorial in order to tell the attendees the truth about Jerry.
Mike is played by Lee Arenberg.