If u discover a monster then u automatically gain 100gil
These r the monsters that have already been discovered:
Acrophie
1st Ray
8 Eye
Serpent
Adamantaimai
Ark Dragon
Joker
Blugu
Bomb
Egg
Aero Combatant
Soldier
An Amored Golem
Allemagne
Brain Pod
Bullmotor
Bagnarada
Attack Squad
Jumping