Blue Bubble

Blue Bubbles are a cursed variation of Bubble that have appeared several times throughout the Zelda series. They almost always require killing only through the loss of their blue color.

Ocarina of Time and Majora's Mask
Blue Bubbles, like other Bubbles, are floating skulls that attack Link, yet are different due to their immersion in a blue flame. They can easily be defended with a shield, and doing so will actually cause them to lose their fiery blanket. They also seem to possess an attraction to bombs, as throwing one near them results in their circling around it until it explodes. In Majora's Mask, their blue flame curses Link on contact, and will render him unable to use his sword. The hex fades away over time, yet can be instantly be removed by performing the Song of Storms.

The Legend of Zelda: The Wind Waker
Now cel-shaded like the rest of the game, Blue Bubbles reappear in Wind Waker and have the same cursing abilities as the Blue Bubbles in Majora's Mask. However, the skulls now render Link unable to use any items at all, and the curse can only be lifted through time. To remove their blue fire, Link must use his Deku Leaf, Hookshot, or use the Ice Arrows to kill them instantly.