Suspicious Looking Eye

The Suspicious Looking Eye is used to summon the Eye of Cthulhu boss. It can be crafted at a Demon Altar at the cost of 6 Lens. It can also be found rarely in Golden Chests. The boss can only be successfully summoned at Night; if the eye is used during the Day nothing will happen and it will not be consumed. Take note that if the Eye of Cthulhu isn't defeated by dawn it will disappear.

Trivia

 * The Suspicious Looking Eye looks similar to both the Servant of Cthulhu and the Demon Eye.
 * If you summon the Eye of Cthulhu right as it turns night, it may not spawn and you will lose your Suspicious Looking Eye.