A stereotypical person is one who is the image of a stereotype. It is NOT (I repeat, NOT!!!!) a person who believes that stereotypes are true. Only a stereotypical foreigner would think this, because the stereotype of foreigners is that they are bad at English. The fact that I feel this way does not make me stereotypical, because there is no stereotype that urban dictionary users are xenophobic.
The word stereotypical should be used in a sentence the same way you would use the word typical.
Incorrect Use: "That jerk assumed that i'm good at math just cause I'm Asian! He's so stereotypical."
Asian guy:"...It's amazing how long he's lived considering all the genes that have recrossed, one could almost mistake him for old english royality."
(Old English Royalty used to wed their sisters and brothers, to keep their royal blood "Pure")