Antler

 is the deity which the nightkin believe in. They believe he/she gives them their orders. Antler is really just a brahmin skull.

Appearances
is only mentioned in Fallout: New Vegas.

Origin
As you can infer from dialougue with Davison, Antler was actually just a BRAHMIN skull Davison picked up while his squad was wandering the wasteland. Since Nightkin suffer from schizophernia due to prolonged use of the stealth boy they thought it was actually a god speaking to them.