I just don't understand object heads? I've seen one that was pretty cool, but beyond that one I just don't really understand or like them very often. It doesn't help that the vast majority just seem to be television heads.
I actually like the strange coloured teeth, but only on ferals. The moment an anthro or humanoid have strange coloured teeth I just find it a bit odd. More than that though, odd-coloured blood, like a neon green, is really weird.
"Cute", frilly, pastel characters aren't bad by any means, but they really aren't the type of character I can ever find a use for.
"Psychotic, murderous doctor" characters... you know, those pink and frilly characters with a surgical mask who are often seen splattered in blood? I really don't like those.
Extra eyes beyond 4-6, or odd numbered eyes for some reason make me uncomfortable. (i.e. 2, 4, 6 are fine but anything else, 1, 9, ect, make me oddly uncomfortable)