Alex Kidd was before Sonic (Sega’s mascot) the first character created by developers like Sega Kotaro Hayashida and Rieko Kodama. Alex kidd appeared for the first time in 1980 in the game Fantazy Zone as the official mascot of Sega. He gets his first game in 1986; Alex Kidd in Miracle World. Interestingly, in the cartridge version of the game, the character has the head and fists disproportionate and feeds onigris (rice dumpling) while in the version included in the console he eats a hamburger. In fact, Alex is a 14 year old boy (manga style) from the 1980s inspired by Bruce Lee and Sun Wukong.
Unfortunately, the character would know have a few years of glory, too Japanese at heart, he was not really suited at the time for the international market. Moreover, with the onset of Genesis, Sega definitely wanted younger looking mascot. Alex Kidd was too childish and no longer corresponded to the image of the company. Sega had therefore created a new mascot able to seduce the North American market. Sonic the Hedgehog was born in 1991.