what is j-cat
General Edit. 1  J-Cat is slang for a prisoner that needs mental health treatment. 2  When the carpeters arrive, the company van says Muensch's Carpets. 3  This marks the fourth time that John Abruzzi doesn't appear in an episode. 4  This marks the first appearance of Charles Patoshik since Cute Poison, a re-appearance of 13 episodes.