Nazar

The Nazar is an accessory that grants immunity to any Cursed debuffs. It has a 1% drop chance from Cursed Skulls, Cursed Hammers, Enchanted Swords, and Crimson Axes. It is one of the few components of the Ankh Charm/Ankh Shield that can be obtained prior to Hardmode. Despite this, it is very hard to get it as none of the monsters which drop it spawn very often.

Trivia

 * A nazar is an eye-shaped charm commonly found in the Middle East meant to ward away the Evil Eye. The word "nazar" is derived from the Arabic "نظر", meaning "sight" or "seeing".
 * Probably the best way to attain one of these is to go into a Hardmode Dungeon with a water candle/battle potions and farm the Cursed Skulls and Cursed Hammers there because 2 of the 4 Nazar-dropping NPC's spawn there. The other two both spawn in different locations.