A particularly fierce creature, Salusan bulls were kept in Caladan. Stablemaster Yresk tended the bulls for Duke Paulus Atreides for his occasional spectacles; however a Salusan bull was responsible for the death of Duke Paulus Atreides. After the Old Duke's death, the bull was slain. During the reign of Leto the Just, the bull's head was mounted and hung on the wall of the Atreides dining hall, firstly on Caladan, then on Arrakis.