A girl who, besides having grotesque or deformed genitalia, is otherwise completely attractive. The nature of her genital abnormality
may differ widely in terms of its cause, type or level of severity. Cited problems
may include, but are not limited to, size, odor, unsightliness etc.
The phrasing of this term is derived from the common colloquialism:
Butterface.
"Yo,
man, I thought that girl was hot, until she
got naked. She was a total buttervag."