He climbs up the down escalator and wears his underwear on the outside of his pants. He buzzes through life carefree. Instead of focusing teenage drama he keeps his attention on his carrot sticks and science projects. It is this complete no worries attitude that makes Alex so loveable.
As Jane and Carl say, the only thing you can say about their Swahili-speaking, Unicorn-loving friend is 'he's Alex'. He rarely has a major role in episodes and tends to be there for comedic value only, such as when he is Carl's gag man in 'Montclaire on the Air'. Also it was revealed that he works at a pizza place in I Carly.
Shadow Alex is Mrs. Montclairs son, Alex Montclaire. Alex werars the same clothes as Carl and loves brownies.