Peridot fields is where you will first train/level up your character, spread throughout the map are various different mobs, some of which are friendly, and some of which are hostile.

Mobs Include [In order of difficulty, easiest to hardest] :

Giant Frog.

River Tortoise.

Shroomback Tortoise.

Wild Boar.

Shroom Guard.

Mine Goblin.

Red Acrobat Ant.

Giant Black Ant.