Someone who hangs at the train station or bus stop or anywhere public all day long, usually asking for a cigarette, spare change or pocket lint. Usually unemployed and unemployable, using nothing but slang, and usually impossible to get rid of, until threatened with violence.
Called magpies because if they have gotten it once, they'll expect it again, and again, regardless of who it is.
Person 1 : Yeah, so anyway, me and this chick...
Magpie : 'Ey man, u gutta spare smoke i can borrow??
Person 1 : No, go away
Magpie : Please man, i havent had one all day...please....
Person 1 : I saw you smoking 10 minutes ago, fuck off
Person 2 : GO AWAY you fucking mapie
Magpie : Pleeaase man, i'll pay you back