Pisces, the Fish, is a sign of the Zodiac and a recurring symbol in the Final Fantasy series.
Pisces is one of the twelve Zodiac Stones. Isilud Tengille, son of the Knights Templar leader Folmarv Tengille, is entrusted with the Artefact by his father. Isilud has no idea of the Lucavi plot and the possession of his father, and is thus unaware is the power within Pisces. When Isilud is killed by his father's rampage through Riovanes Castle, he gives the stone to Alma Beoulve as he dies. Alma loses the stone when she is kidnapped by Folmarv, but it is later recovered by her brother Ramza.
Pisces is also a zodiac sign used to determine damage compatibility between characters during battle. Units with good compatibility will do higher damage to each other, and the opposite is true for signs with bad compatibility. Signs with optimal compatibility do extreme damage to units of the opposite sex but meager damage to units of the same sex.