An alleged former Sega employee under the online handle "Super Magnetic" has posted pictures of an unreleased Sega console on the Assembler Games forum.
The post states that the device is called the Sega Pluto, which is a Sega Saturn console with a Netlink modem built into the system. The system weighs in at 2.8kg and has two controller ports, a flip-top drive bay, and a cart slot. The machine has the Sega Saturn logo on top of it, which could infer that the device was to be marketed as a new SKU for the Sega Saturn.
According to the forum member, there are only two known prototypes of the hardware in existence. The device the forum member is currently holding is in working order and can play NTSC US Sega Saturn games. The Netlink modem was compatible with a number of Sega Saturn titles like Saturn Bomberman and Virtual-On.