Retreats behind the column after taking damage, where it cannot be attacked. Hits all targets with Nautilus Charge on the next turn, inflicting great damage. Use trigger commands to stop it from unleashing Nautilus Charge.
After losing 350 HP, Tros will retreat to opposite side of the chamber. The party can no longer attack (unless the player uses Rikku to toss grenades) but can initiate a Trigger Command called Stand By to recover 50 HP each. Tros will use its Nautilus Charge attack which deals heavy damage. After 350 HP more is lost, the fiend will again retreat. This time Tidus can select Pincer Attack from the Trigger Command menu and tell Rikku to swim in front of Tros, while Tidus swims behind it. It will no longer be able to use Nautilus Charge.
Tros was a ruler of Troy and the son of Erichthonius by Astyoche (daughter of the river god Simoeis) or of Ilus I, from whom he inherited the throne.In Greek mythology,
Given its appearance as an octopus and its purple coloration, it may be a reference to Ultros.
- Tros has two unusual properties which would generally never be seen without hacking the game (although the former is possible to see by using the Expert Sphere Grid and major level grinding). The first is that Tros is vulnerable to Poison, but if afflicted takes no damage from it. The second is that, despite being a boss and not appearing anywhere else in the game, Tros can be captured. It will not show up in the Monster Arena if captured, but the game will say it was captured instead of saying it cannot be, if it is killed with a capture weapon. Furthermore, this capture is recorded in the save file.