Phoenix tears

The tears  of a phoenix have immense healing powers. It is the only known cure for the basilisk venom. It is also capable of reviving a person from any injury, even if the person is at the brink of death.

Fawkes produced his tears to heal Harry Potter when the latter was bitten by Salazar Slytherin's Basilisk during the battle in the Chamber of Secrets, which not only sealed the wound, but also cleared the poison out of Harry before he died from it.

Appearances

 * Harry Potter and the Chamber of Secrets
 * Harry Potter and the Chamber of Secrets (film)
 * Harry Potter and the Deathly Hallows