Cross Necklace

The Cross Necklace is a Hardmode Accessory that doubles the duration of the invincibility a player is afforded after taking damage, from 2/3 of a second to 1 1/3 seconds. It has no effect in PvP. The Cross Necklace is dropped by Mimics.

The Cross Necklace is useful in Hardmode Boss fights, and any other scenario where the player is likely to be hit in rapid succession.

Trivia

 * This item may be a reference to the Cross Pendant in first Castlevania game, having nearly the same image and making the player invincible for a short duration, except that item also cleared the screen of enemies, rather than increasing their "mercy invulnerability".