Ekajati: Tara protectress Wrathful Grandmother: One of the 21 Taras of Tibetan Buddhism

Ekajati or Ekadzati (Tib. Ralchikma or Tsechikma) is the Nyingma Dzogchen protector of mantras (Ngag Sungma) and mind-treasure (Tib. terma) whose epithet, "One Braid" (or, plait) refers to her initially terrifying appearance since she has only one eye, one tooth, one breast and so on.
end partial quote from:
http://www.khandro.net/deities_female.htm

While traveling in Dharamshala, India and before I heard about the Wrafthful protectress who is one of the 21 Taras of Tibetan Buddhism. When one gives the Tara mantra one is asking for the 21 Taras to free oneself, one's family and all nearby from the 8 Great Terrors. Some of the 8 great terrors are being Burnt to death, Drowning, being stabbed, STrangled etc. So, basically by doing the Tara Mantra one is preventing a violent or accidental death. This is done so one can consciously choose what heaven one goes to while they are passing on.

Another Tara protectress is "White Tara" who is the long life protectress who especially gives long life to "Living Buddhas" and others who pray to her for help.

Tara could be compared in other cultures to Mary, the Mother of Jesus or to Kwan Yin, the Goddess of Mercy. All are female mother protector dieties.