Answer: Sonic the Hedgehog
Early in the battle between Nintendo and Sega, one thing became abundantly clear—Nintendo had vastly better branding with a radically more recognizable mascot. Everybody and their grandmother knew who Mario was and next to nobody knew who the Sega company mascot was. If you’re straining really hard to remember who Sega’s 1980s era mascot was, we’ll spare you the agony—it was a pudgy, short boy with monkey-like features named Alex Kidd.
In order to compete with Nintendo, Sega held an internal company contest to come up with a really recognizable and fun character to become the new mascot. The contest proved very fruitful and numerous submissions became Sega characters (Mighty the Armadillo, Dr. Robotnik, and others all appeared in early forms as a result of the contest). The most notable submission, however, was by employee Naota Ohshima—a teal-colored anthropomorphic animal he called “Mr. Needlemouse”. His creation won the contest and Sega slightly tweaked the idea into a cobalt blue color with a new name, “Sonic the Hedgehog”. Lest you think Sega took too many liberties with the redesign, know that “needlemouse” is a literal translation of the Japanese word for hedgehog.
The fun, colorful character and the speedy play style of the game combined with the decision to bundle Sonic the Hedgehog with the Sega Genesis is widely regarded as the key change that helped Sega gain 65 percent of the market share for 16-bit consoles in the battle against Nintendo.
Image courtesy of Naota Ohshima/Sega from The History of Sonic the Hedgehog.