Doctor Robotnik (Sonic the Hedgehog: The Movie)

Dr. Robotnik is an alternate version of Dr. Ivo Robotnik from Planet Freedom in an unnamed Zone who wishes to marry Princess Sara. Sonic the Hedgehog and Tails did battle with him and his Metal Robotnik robot briefly after their Mobius was altered to resemble his dimension by the efforts of Chaos Knuckles. The restoration of reality ended this incident and possibly erased it from the minds of those on Mobius. (StH: #101)

Background Information
Despite being a nod to the Robotnik from Sonic the Hedgehog: The Movie, this Robotnik's origins appear to be different. Like the OVA version, this Robotnik lived on Planet Freedom, though his hostage is referred to as "Princess Sara," whereas in the OVA, Sara was not a princess, but the daughter of the President of South Island.