Dr. Robotnik first appearance was in the 1991 video game Sonic the Hedgehog for the Sega Mega Drive/Genesis. He attempted to find the powerful Chaos Emeralds by conquering South Island and turning its Animals into robots. Launching a full-scale assault, Robotnik was able to seize control over countless cities, factories, and lands, and transformed them into his image and polluted the very environment with his fortresses. Robotnik ordered his vast army to search for the Chaos Emeralds and build weapons of mass destruction so that his dominance would never be challenged. Luckily, Sonic the Hedgehog sped to the rescue, defeated Robotnik, saved the animals from roboticization, and retrieved the Chaos Emeralds. Thus the island was restored to its former, peaceful state.