HP: 265

Melusine is a Reptile-type enemy that you can find in the Thunder Plains. You need to capture five of each Reptile-type enemy to unlock Ornitholestes in the Species Conquest section of the Monster Arena.

Defeating Melusine is very easy to do. One swing from Tidus’ Longsword or Wakka’s Blitzball should do the trick. Defeat them quickly, though, as their regular attacks can cause Petrification and Silence.

Ability	Description
Sensor	“Very nimble. Resistant to magic. Watch out for petrification and silence.”
Scan	“Very nimble and hard to hit. Magic defense is also high. Takes only half damage from fire, lightning and water. Attacks may cause petrification and silence.”

Steal:
Soft (common)
Petrify Grenade (rare)

Drops:
Speed Sphere (common)
Power Sphere (rare)

Location

You can find them anywhere in the Thunder Plains. They tend to be more abundant in the first section of the Thunder Plains.