The Polaroid

The Polaroid is an unlockable passive item.

Effects

 * If the character has half a red heart or no red hearts after taking damage, it triggers the Book Of Shadows effect, creating a shield that nullifies all types of damage for 5 seconds.
 * Allows entrance into The Chest after beating Isaac in the Cathedral by touching the chest.

Trivia

 * In the original Binding of Isaac flash game, The Polaroid used to be a trinket that Mom would drop in addition to a regular collectible from the boss pool. When it was originally implemented, it was only available in the normal Trinket drop pool and was implemented secretively. Players were frustrated, so, with an update, Edmund made it so it would also only drop if the player took no red heart damage against Mom, similar to the conditions for the Devil Room to open its path. Since players would not always receive the Polaroid and might switch it out with another trinket, Edmund wanted to make discovery of The Chest (and its at-the-time new ending) something special.
 * As soon as The Polaroid or The Negative become available, they will drop in place of the regular Boss Room item Mom would otherwise provide, essentially providing a difficulty increase for The Womb and beyond after either has been unlocked.
 * They can, however, be re-rolled at the cost of closing off access to Chapter 6.

Seeds
NTKG 9MMP (Starting item for Eden)