Izzy Mandelbaum, Jr. is a character in Seinfeld.
Izzy Mandelbaum, Jr. is the son of Izzy Mandelbaum and the grandson of Izzy Mandelbaum, Sr. When Jerry Seinfeld first noticed Izzy Jr. and saw he was old, Izzy stated that he got married in high school.
In "The English Patient," Izzy Jr. visited his father in the hospital where he heard about Jerry's "challenge" to Izzy. Izzy Jr. tried to compete against Jerry by lifting the TV in the room only to end up throwing out his back. Now hospitalized, Izzy Jr. asked why nobody told him that the TV was bolted down. This same incident with the TV later happens to Izzy Sr.
In "The Blood," Izzy Jr. assisted his father in training Jerry where he would jog with the other rope that is tied to him is tied to Jerry's car which Izzy Jr. drives. During this routine, Izzy Jr. tells his father and Jerry that a red liquid is dripping on his feet when the car starts having problems. When Izzy Jr. identifies it as blood, Jerry faints and gets dragged along enough for him to end up in the hospital.