Board Thread:Naruto Discussions/@comment-25228549-20140821104935/@comment-1512913-20140823200530

@Seel:
 * Mythical Tanuki are exclusively male I believe? Large scrotum/testicles and all I mean. As was brought up, Gaara's gourd resembles said organ.
 * Son Goku is clearly a male, muscular stature, being King and all.
 * Oxes/bulls are male, so Gyuki is a male.

That is "non-psychological" so we have 3 Tailed Beasts with obvious sex.