Common characteristics are:
1) Work 24/7, socialize/do other stuff 0/0.
2) Walk quickly and nervously, avoiding eye contact with anyone.
3) Goofy foreign outfits such as soccer uniforms, short shorts for guys, and ridiculously conservative/plain outfits for girls, with goofy foreign shoulder packs.
4) Thick black-rimmed glasses.
5) Scrawny stature and pockmarked face.
6) Shuffle nervously through notes during exams, dropping things, sweating profusely, and freaking out.
7) Think that the professor saying "Stop working NOW" on an exam means the same thing as "15-minute warning," and will keep working furiously until the exam is physically snatched out of their hand.
8) Friday night all-nighters of studying and spreadsheet analysis marathons with breaks every few hours for Anime porn.
9) Ask incomprehensible, mumbling, irrelevant questions in lecture.
10) Despite their eagerness in lecture, speak at an inaudible volume, if at all, in social situations.
11) Score 114 points on a test where only 100 are possible.
12) Argue with the TA for 2 hours about one point on a problem set that's worth 2% of the overall grade.
13) Have the problem set finished before you realized it had been handed out.
14) Act like a major douche bag in any and all circumstances.
15) Use their knowledge they learn from American schools to start foreign companies that destroy American companies in the market since their labor forces consist primarily of starving 6-year-olds working 20 hours a day for 2 cents and a bowl of rice.
"OK...Sujeep, Chong-Ming, and Hassam...you guys are the FMF's in this group, and therefore you're all ridiculously smart and overachieving socially awkward douche bags. So you guys handle all the mathematical shit, data analysis, and charts...basically you do all the work for this...and then Dave and I will translate your incoherent foreign bullshit into understandable English."