Peter A Goldsbury
One shihan who used to do kubi-nage (kubi means neck, by the way, not head) was the late Morihiro Saito. At a seminar I attended he was doing it from kata-dori. He broke uke's balance, took the head, now in range of atemi, and twisted the neck (which is why it is dangerous). Hence the name.
Something like this
, but here is called kumi nage (probably a typo)