There are two versions of the boss "Junior". In the arcade machine is a switch that will change the boss of the Freak Show from a big baby to a gigantic teddy bear named Deaddy. It's likely that the switch was added to avoid complaints from parents regarding the shooting of an infant child.
Contributed by CLXcool
Inside the game's files is an unused image of Jeffrey Dahmer holding a paper bag with the head of Neil Nicastro (executive producer, and CEO of Midway Games until 2004) in it. The image appears several times in various sizes, and was most likely used to fill empty space in the game's data.
Contributed by DeerBoarDude