For the story of the same name, see Splitzoid (story).
Splitzoid is an android created by Doctor Robotnik and Grimer. The villain was designed and developed in one of the New Zones; Robotnik took advantage of not having a bad reputation in these new areas and utilised their superior technology. Splitzoid's mission was to visit the Emerald Hill Zone and kill Sonic the Hedgehog, something the robot began to do by invading the Zone through the Eternity Ring. Splitzoid took an early advantage over Sonic and things got worse when a well-aimed Spin Attack only served to replicate Splitzoid, literally splitting it in two. A similar crossbow attack from Amy Rose saw Splitzoid create a second copy. Seeing the problem, Sonic ran to the Icecap Zone to draw the Splitzoids from the village.
All three versions were able to easily keep up with Sonic and followed him to the icy region, only to be engulfed by an avalanche. Splitzoid survived and all three versions created a new copy, bringing the Splitzoid count to 6. Fortunately for the heroes, the continuation of replication slowed most of them to a crawl. Realising that the original Splitzoid was still going strong, Sonic encouraged to follow him into a cave and found itself attacked by an old Ice Jet. A seventh Splitzoid was created but both 1 and 7 were encased inside an ice block and the other copies deactivated.
- Splitzoid One's codename is R-G 1, short for "Robotnik-Grimer 1", the robot's creators.
- Splitzoid is the second villain to come through the Eternity Ring, following Set.