|First Appearance||"The Gum"|
|Last Appearance||"The Bottle Deposit"|
|Portrayed By||Mary Jo Keenen|
Deena Lazzari is a childhood friend of George Costanza. She believes that George is mentally unstable after she repeatedly catches him in bizarre situations. First, in “The Gum”, she notices striking similarities between George's behavior and that of her mentally unstable father (affectionately known by all as Pop Lazzari), that being "nervousness, irritability, and paranoia". Her suspicions are heightened when she sees him walking down the street in a King Henry VIII costume telling people he just left the 'institution'. Then, in “The Doll”, she catches him in the coffee shop, alone and screaming at a doll that looks like his mother. Finally, in “The Bottle Deposit” she is visiting her father at the mental asylum when she runs into a hysterical George, who was mistakenly sent there by George Steinbrenner. She ignores his pleas to help him escape, believing that he is finally getting the help he needs. She is portrayed by Mary Jo Keenen of Nurses fame.