Eye of Cthulhu

Calling it, or being called on

Most players meet it on purpose: craft a Suspicious Looking Eye from six Lenses at a Demon or Crimson Altar and use it after dark. Lenses drop from Demon Eyes, so a couple of nights on the surface usually covers it.

It can also turn up uninvited. Once a character has some extra life and armor and a few town NPCs have moved in, any night can open with You feel an evil presence watching you... and the boss arrives a little later. It leaves at dawn whether it is winning or not, so a fight that goes badly can simply be outlasted.

Getting ready

With 2,800 life in Classic (3,640 in Expert, 4,641 in Master), it is a damage check more than a dodging test. Things that help most:

• A long, flat arena: a few rows of wooden platforms high above the ground let you run sideways and drop through when it dashes. Walls do nothing; it flies through blocks.
• A ranged weapon with plenty of ammo: any bow with a stack of Flaming or Jester's Arrows, a Minishark from the Arms Dealer, or an Enchanted Sword if your world has one near spawn.
• Healing on hand: a Campfire on the arena, Lesser Healing Potions, and Ironskin and Regeneration potions if you have the herbs.
• Movement: Hermes Boots or any double jump turn its charges into near misses.

The two forms

In its first form it hovers above you, spits out small Servants of Cthulhu, then charges a few times in a row before backing off to do it again. Kill the Servants as they come: they die in a hit or two and the field stays clear.

At half life it spins in place and tears off its eye, revealing a mouth. This second form stops calling Servants, loses all its defense and hits harder: contact damage climbs from 15 to well above that. It charges faster and more often, so keep moving sideways and keep firing. In Expert and Master the low-life stretch adds a burst of rapid charges with barely a pause between them; save your movement accessory for that part.

What it leaves behind

In Classic it always drops 30–90 Demonite Ore in a Corruption world (30–90 Crimtane Ore in a Crimson one), a few evil seeds and a stack of Unholy Arrows. The ore is the point: it is enough for a set of evil-ore weapons and tools well before you could break Shadow Orbs safely. The mask drops 14.3% of the time and the Binoculars 2.5%.

In Expert and Master everything comes in a Treasure Bag, which adds the Shield of Cthulhu: a dash on a double tap that stays useful long into Hardmode. Because the summon item is cheap, fighting it again for ore is a fair way to fund an early kit.

Once it is beaten it no longer shows up on its own, and the Dryad becomes able to move in, with Purification Powder to push back the evil around your base.

Trivia

• Its Bestiary entry calls it a piece of Cthulhu torn from his body in an ancient war.
• It was one of the first bosses in the game, alongside the Eater of Worlds and Skeletron.