Probic vent
From Tardis Wiki, the free Doctor Who reference
The Probic Vent is a part of Sontaran anatomy. The Probic Vent is a small metallic tube attached to the back of the Sontaran's neck. This Probic Vent is normally used by the Sontarans as a feeding tube during space or time-flight. The Vent is also a major weakness, since a blow to the Probic Vent had knock a Sontaran unconscious or even kill them. The Sontarans don't find it to be a problem, however, since it means they must always face their enemy.
File:St--3u50linxshot.jpg
The Sontaran Linx lies dead in his ship after being punctured in the probic vent by an arrow. (DW: The Time Warrior)
