Sacred Beast is a fiend type in Final Fantasy X and Final Fantasy X-2. Usually characterized as a large ancient dragons, they are one of the more powerful species in Spira, having one of the highest HP of normal bosses, as well as being able to severely damage all party members with devastating attacks that inflict a myriad of status ailments.
Their signature attacks is Mana Breath that more often than not is a guaranteed KO on whoever it targets. They are typically found guarding paths or treasures, such as the path to Zanarkand or dresspheres. In Final Fantasy X-2 it takes 10 kills to Oversoul a Sacred Beast.