The enemy is fairly easy during the events of Part I; due to the fact it uses weak physical attacks and has no special abilities. It can be defeated quickly by attacking it with the Aero spell and standard physical attacks. After Part II begins, the Big Worms on the world map and inside the Moonlight Tower are replaced with the Wyorm enemy.
During Part II, Big Worms can only be found inside the Mysterious Lighthouse bonus dungeon. Big Worms can be tough enemies to defeat once they use Vitriol on the enemy, which inflicts Suppress on the target. When fighting Big Worms, the player should have two party members attack with Bladeblitz and Aeroga, while the other party members use Lux or the Bard's abilities to cancel the status down effect.