Sometimes he appeared as a teenager, although the only time his exactural age has been stated, he was stated to be 14 years old. However, being a 14-year-old Arian was somewhat different to being a 14-year-old human. He has lived many hundreds of years previously.
Disregarding the various costumes he would adorn in the later Alex Kidd titles, the initial appearance of the character would swing between garb loosely resembling a traditional Mandarin tunic, or red striped jumpsuit (Sometimes overalls closer to the appearance of Mario depending on the localisation).
At a glance its easy to see that the character of Alex Kidd was inspired chiefly by Bruce Lee (evident in the jump suit) and Sun Wukong the Monkey King. In the mid-to-late 1980s, Alex Kidd overtook the character of "Opa-Opa" from the game Fantasy Zone as the official mascot for Sega. However, Sega wished to have a mascot to rival Nintendo's flagship character Mario, a task which Alex Kidd was not considered up to.
In 1991, Sega introduced Sonic the Hedgehog, who became more popular and recognizable than Alex Kidd, and Sonic subsequently replaced Alex Kidd as Sega's mascot. After this, the popularity of the character waned somewhat, although the character has made numerous cameo appearances in later video games, most recently in Sega Superstars Tennis, Sonic & Sega All-Stars Racing and Sonic & All-Stars Racing Transformed.