When Laverne (Penny Marshall) chips a tooth, it is manna from heaven for novice dentist Mikey (Bob McClurg)--who happens to be the cousin of Laverne's roommate Shirley (Cindy Williams). A lifelong failure (he has already flunked out of dentist school five times!), Mikey hopes to prove his worth by taking good care of Laverne--but no one has reckoned with the perilously persuasive powers of nitrous oxide, aka "laughing gas." Eddie Mekka (Carmine) sings "Personality", originally written for the 1945 Hope-Crosby comedy Road to Utopia.