Stratoavis is an enemy from Final Fantasy X fought at the Monster Arena in the Area Conquest once the player has caught at least one of each of the three fiends in Besaid: Dingo, Condor and Water Flan.
Its appearance is exactly like the Zu from Bikanel and acts in a similar manner by making its wings glow and then using Paean of the Heavens on its next turn, which deals fractional damage to the entire party, equal to 15/16 of each character's maximum HP and inflicts Darkness and Delay (strong). Also like Zu, Stratoavis will not die if reduced to 0 HP while still in the air; he will land with 1 HP remaining.
Stratoavis can drop equipment with two to four slots with one to three having abilities, with weapons having Magic +5%, Magic +10%, and/or Magic +20% (fixed). The armor drops have HP +30% as fixed ability, but other slots can also have HP +10% or HP +20%.
Stratoavis is not immune to Slow attacks, but it will only work 10% of the time because of its Slow Resist. The same can be said about Armor Break. A Frag Grenade or Auron's Banishing Blade Overdrive work 100% of the time (if successful), and so are more effective to break its Full Break resistance.
Once Stratoavis has landed, summoning Shiva ensures Stratoavis has little to no chance of hitting her.