Eye of Cthulhu's twin

How to Summon
You will need 6 black lens to craft the item that summons him, the item is called The Eye of Mysteries. (You need to craft it on a Demon Alter.) After you do that, you need to wait for night, and when it's night, hold to summon. (He can only be summoned in hard mode.)

The Fight
The Eye of Cthulhu's twin is also called The Eye of Terror, he shoots orange plasma balls at you, they do 5 hearts of damage, tops. The Eye of Terror has 3 times the health of The Eye of Cthulhu. Once you defeat him, you will earn a weapon called The Plasma Shooter, which shoots plasma balls.