boss

Eye of Cthulhu

The first mandatory pre-Hardmode boss. Summoned with a Suspicious Looking Eye or by low HP at night.

Pre-HardmodePre-Hardmode1.4.5.6#2

The Eye of Cthulhu is usually the first boss most players meet. It can appear on its own once your HP drops below 200 at night (a 33% chance each night after that threshold), or you can force the fight any time with a Suspicious Looking Eye, crafted at a Shadow/Demon Altar from 6 Lens dropped by regular Demon Eyes.

Type: Pre-Hardmode boss
Health: 2,800 (2,800 × co-op scaling)
Summon: Suspicious Looking Eye / random at night
Biome: Surface, night
Drops: Demonite/Crimtane Ore, possibly a movement accessory

Phase 1 — Dash

The Eye slowly hovers and periodically charges straight at you. Keep moving sideways and hit it between dashes with ranged or melee weapons.

Phase 2 — Servants & faster

Below 50% HP it opens its iris, spawns 2–4 Servants of Cthulhu and dashes much faster. Prioritise dodging; a small arena with wooden platforms helps.

Strategy

Build a long wooden platform arena (~50 blocks) with campfires and a few sunflowers.
Use Shackle + Hermes Boots for mobility; a Boomstick or Silver Bullets work well.
In Phase 2, keep a Grappling Hook ready and don't stand still — the fast dashes punish camping.
Melee users: a Gold Broadsword or Bone Sword plus a shield is fine.