Hero's Charm

The Hero's Charm is a golden Mask in The Wind Waker that is quite useful and ingenious; it reveals an enemy's life meter, so that Link can visualize the amount of damage inflicted per strike upon a particular enemy. Enemy life energy appears as a green bar next to the foe when it is targeted. The Hero's Charm is given to Link as a memento after trading Mrs. Marie, the kindly teacher who resides in the main square of Windfall Island, an extra 40 Joy Pendants. Link must have already received the Cabana Deed from Mrs. Marie before having the opportunity to obtain the Hero's Charm, as the Cabana Deed was a previous gift for handing Mrs. Marie Link's first 20 Joy Pendants.

Interestingly, the Hero's Charm also functions during boss fights, excluding Ganondorf, in which the boss' life meter is displayed at the bottom of the screen, as opposed to nearby.

Trivia

 * The Hero's Charm marks the first time in the Zelda series that an enemy's life meter can be visualized.
 * The two eyes on the mask resemble the Sheikah eye symbol.