Fake Flakey
One who pretends to be slightly psychotic for some percieved advantage from others. 

Symptoms of "Fake Flakeyness" include buying mugs or signs to hang in their place of work with "You don't have to be mad here, but it helps" written on them, saying such things as "I'm mad me", "I'm gonna kill everyone someday", pretending to develop an interest in Hentai or bad slasher movies and also pretending to find random and sometimes controversial subjects hilariously funny. Such as cancer.

This behaviour is highly irritating to people who know the person, as they know that he\she is not actually in any way mentally ill. 

This behaviour is also irritating to people who do not know the person, as they will at the very least be wary of such a person.
"Did you hear? Darius threatened to kill everyone again."

"Man, he is such a fake flakey, no wonder people tend to avoid him."

Many wannabe Goths and Emo kids tend towards Fake Flakey behaviour.