Baby John (Eliot Feld) is a "rank and file" member of the Jets, having been given his nickname because he is the youngest and newest member. He is also the most naïve as he usually asks questions about gang logistics, particularly if and when the police get wind of whatever they're up to at the time. He is also the most hesitant of the gang; when Riff decides the Jets are going to take on the Sharks in an all-out fight, Baby John says "I say let's forget the whole thing".
Having not been fully acclimated to their street culture, Baby John is also the most sensitive of the Jets, but he is careful to not wear his heart on his sleeve in front of the others. After the rumble, during which Riff was killed by Bernardo, Baby John is in hiding and crying when he is found by A-Rab, his closest friend. Later when the two meet up with the surviving Jets, Action starts to get on Baby John's case, but A-Rab stands up for him.