Thanks Laura, thanks vicente for your replies...
It's much clearer now... Have you seen the movie "Sixth sense"? The little boy was called "freak" by his friends because he was kind of weird (he actually was,
he could see dead people). That word is heard many times in that film and I remember it was translated as "monstruo" or "fenómeno". He says something like "My friends call me freak"... I don't like those words. I like Laura's suggestion... raro/a... what do you think?