Izzy Mandelbaum, Sr. is the father of Izzy Mandelbaum and the grandfather of Izzy Mandelbaum, Jr.
He appeared in "The English Patient" where he visits his son and grandson in the hospital. When they hear about Jerry Seinfeld's "challenges" to him, Izzy Sr. tries to lift the TV in their hospital room only to throw out his back as well and end up hospitalized. When in his hospital bed, Izzy Sr. asked why nobody told him that the TV was bolted down.