The team developed ideas for characters, an engine, and gameplay mechanics. Development emphasized speed, so Sega considered fast creatures such as kangaroos and squirrels and eliminated designs not associated with fast animals. One idea, a rabbit able to grasp objects with prehensile ears, showed promise but was too complex for the Genesis hardware. The team narrowed its search to animals that could roll into a ball, their idea for an attacking move. Deciding this would not seem aggressive enough, they focused on animals with spikes: armadillos and hedgehogs. The hedgehog character, proposed by Naoto Ohshima, prevailed; the armadillo became the basis for Mighty the Armadillo, who appeared in 1993's "SegaSonic the Hedgehog". Ohshima said he created Sonic's basic design by combining Felix the Cat's head with Mickey Mouse's body. His inspiration for creating Sonic was Sega wanting a game that would be successful in the United States and a new mascot concurrently. Ohshima was thinking of design ideas with the toy and stationery department. Before Sonic was chosen, other characters, including a rabbit and a bearded man who became Dr. Robotnik, were created. Ohshima went on vacation to New York, taking sketches with him. He went to Central Park and asked locals for their opinions on them, and Sonic was the favorite. Ohshima explained that this was because he wanted support for his ideas.