The name Amoghasiddhi means " Almighty Conqueror " or " He Who Unerringly Achieves His Goal."
He is a Dhyani Buddha within Vajrayana Buddhism, described as the buddha of the realization of the Bodhisattva Path, and residing in the northern quadrant of a mandala. He rules over the element of Air and embodies the skandha of volition, also called the skandha of mental phenomena or tendencies of mind. His consort is Green Tara representing the Wisdom of Accomplishment, or Wisdom of Perfected Action.
Amoghasiddhi's bija (seed word) is Ah and his mantra is Om Amoghasiddhi Ah.
His body is green in color and the right hand is placed in the mudra of abhaya - fearlessness and protection. This gesture signifies that the devotee, through the Buddhist Dharma, is being taught to overcome the fear of death, and to subsequently achieve the final release from the cycle of rebirth. In essence, Amoghasiddhi represents the practical realization of the wisdoms of all buddhas. Practitioners who meditate on him attempt to realize within themselves the "attainment through action wisdom" understood as the teaching of the Dharma.