Geoffrey Samuel describes these Gyalpo spirits as "king-spirits" who are "the spirits of evil kings or of high lamas who have failed their vows." He also states that they are white in color. Nebesky-Wojkowitz characterizes this type of spirit as generally red in colour and of violent character, harassing mainly lamas and religious people, but also laity and even animals. In fact Gyalpo spirits often have both white (peaceful) and red (wrathful) forms.