It seems my words were misinterpreted. Let me be clear: I was not making a criticism about the quality of the work; merely a comment on the creepiness of some of them. The graphical quality itself is acceptable. Thus, when I said, "worst" in this context, I meant "most creepy." As for why, probably because it reminds me of the smile people have after they've been poisoned to death by the Joker. If this was part of what you were going for, well then... excellent work. I actually didn't notice any crooked teeth before you mentioned it and had to stare pretty hard at the icon to find them. If anything, the crookedness adds to the piece; straight teeth would look too fake on such a small image. If the Joker smile is not what you were going for, perhaps you could try reducing the amount of space the smile takes up on the nu's face.
I think maggiekarp meant "pee fear," not "fear pee." Makes complete sense that way. If I had to guess why she was disturbed by the winking nu, it might be because the wink on that particular nu is the kind that suggests it is sexually attracted to what it is looking at, and most people are not sexually attracted to nu. If pedo-nu is not what you were going for, perhaps you could try closing his mouth.
And as it so happens,
I did make my own. Almost two years before you made yours, in fact. They never caught on, though, because some of the expressions were too hard to read at the size they were at. Any bigger, though, and they wouldn't fit in-line with a paragraph, like some people have been complaining about yours. It's pretty much impossible to make everyone happy, eh? Since I refused to increase the size, I gave up on the project and offered for anyone to pick up where I left off, having the advantage of starting with the significant graphical resources I had already created. There were no takers. Then
you made your own from scratch 22 months later.
Anyway, calm down. They're just my opinions. Everyone's got 'em.