You can unlock Pteryx by capturing five of each Bird-type fiend, which includes each of the following:
HP: 100,000
Pteryx is a Bird-type fiend, which means it can be challenging to hit with standard attacks. Wakka will be able to hit it with his Blitzball, but you may need to use 
Aim or 
Luck to increase the odds of other party members being able to hit it. Other than that, there isn’t much strategy required.
You should consider power leveling your characters and obtaining the Celestial Weapons, in this case, for Yuna specifically. Check out the Advanced section of the Tips and Tricks for more information. With properly leveled characters, this fight is pretty straightforward.
| Ability | Description |
|---|---|
 Sensor |
“Immune to sensors.” |
| Scan |
“Immune to scans.” |
Steal:
Smoke Bomb (x4) (common)
Candle of Life (rare)
Drops:
Evasion Sphere (common)
Dark Matter (rare)