The Jaguar Duo (or combo) is a prototype of much speculation.  It is either the design mock-up for the Jaguar 2, or the design for the combination Jaguar Mk.1 with CD drive built-in.  It was first seen by developers and other Atari business partners in 1995, and was even shown in an Atari Jaguar advertisement feature in the "Edge" magazine that same year.

It would make sense that engineers at Atari would further evolve the original Jaguar design to incorporate the CD drive, and this would also reduce the manufacturing costs, as Atari were producing two separate hardware units in the Jaguar Mk.1 and CD Player unit.

Unfortunately, this advanced design would not be utilised, as Atari phased out the Jaguar in 1996 and its place in the video games market.