Despite its low HP, Cactuars are tough to defeat as they are agile and difficult to hit. Its high Magic Defense renders magic ineffective. Cactuars have the Armored auto-ability, which means only Piercing weapons can inflict maximum damage. Cactuars use a weak physical attack, but they also use the fearsome 10,000 Needles attack, which inflicts 10,000 points of damage, effectively knocking out its victim.
Cactuars yield a high chance of dropping weapons with Initiative and armor with HP Stroll, MP Stroll, and HP +10%. This, coupled with the amount of AP obtained at this stage of the game, makes the Cactuar a worthwhile enemy to kill.