Cocoon is a Blue Mage skill that is learned from Crawlers. It increases the Defense of the caster by 50 percent. This spell grants VIT+3 when set, and costs one Blue Magic Point to set.

• This spell is self-cast only, except when used after Diffusion, which will cause all party members within the area of effect to gain the effect of the spell.
• This spell overwrites nearly any Defense Down effect.
• This spell is always full-strength, even with Blue Mage set as a subjob. The only variance in its effect comes with the user's Defense stat: after all other defense bonuses are applied, Cocoon multiplies Defense by 1.5.

• This is an extremely potent defensive spell (albeit with a brief duration). For comparison, Protect V, a spell for White Mages at level 76 (and other jobs later), grants only 60 points of defense. For Cocoon to grant only 60 defense, the target's defense would have to be only 120, a very unrealistically low number for players even mid-level.
  • Example of Cocoon's potency: a PLD/BLU with 500 defense casts Cocoon, gaining 250 defense, for a total of 750 defense.
• Cocoon stacks with Protect, Defender, and VIT bonus, but not other Defense Bonus statuses.
• Considering the 1 Blue Magic Point set cost, the VIT+3 bonus for setting, the potency of the spell, and Blue Mages' low natural durability, this spell is a staple of many players' Blue Magic sets from levels 8 to 85 (the level the spell is acquired to the current max level).