Vajrayogini (rdo rje rnal 'byor ma). A semiwrathful yidam. She is red, with one face and two arms, young and beautiful but enraged and wearing ornaments of human bones. She represents the transformation of ignorance and passion into shunyata and compassion.
In India there were many Vajrayogini traditions, only few were transmitted to Tibet.
The Sakya tradition has a special Vajrayogini lineage going back to Naropa, who only transmitted this lineage to the Phamthingka brothers, and from them it was transmitted to the Sakya lineage in Tibet.
rje btsun mkha' spyod rdo rje btsun mo - vajrayogini as khechari [RY]
rje btsun nA ro mkha' spyod ma - vajrayogini khecari teachings handed down from Naropa [RY]
dus mtshan - kalaratri (hindu goddess on whom vajrayogini tramples), king of kalinga, descendant of chakravarti raja [JV]
bdud mgon - maranatha, [Epithet of gayadhara, the protector of the vajrayogini sadhana] [RY]
me - 1) fire, flame, ember [Notes this is to describe the source of dharmas in vajrayogini's secret place, another suggestion was "glowing like a fire mandala"]; 2) anaka, (the 50th year, male fire dragon) [IW]