When I think freak, I think of something you may see in a carnival sideshow. What was called the freak show. I don't think they have tham any more. It wouldn't be politically correct. You know, the bearded lady, the lizard man, the guy with three legs or two heads. Wait, if I think about it, a lot of guys may think of themselves as having three legs or two heads. Anyway, it probably wouldn't have been complimentary.
It also was associated with someone who may have been a heavy drug user and didn't shower often.
I hope, for your sake, you don't have scales, use heroin, and you do own a bar of soap. If you have three legs, you're probably popular with the ladies.