In its first phase, the Eye of Cthulhu possesses the following attacks:
Hover Charge
- The Eye of Cthulhu drifts near the player and attempts to stay above them, then charges slowly towards them.
Charging Servants
- The Eye of Cthulhu drifts overhead at increased speed for 1 second, then quickly comes to a stop and summons 6 Servants of Cthulhu around itself in small bursts of blood.
- The Servants constantly accelerate towards the player with a low turning speed, dying when they strike solid tiles.
Horizontal Blood Charge
- The Eye of Cthulhu quickly moves far above and to the side of the player, then charges horizontally, firing Tooth Balls as it travels which fall to the ground and come to a stop.
- Tooth Balls explode after 5.5 seconds, at which point they fire 2 high-velocity, gravity-affected Teeth upward and at a slight outward angle.
- The Eye deals no contact damage while preparing to charge.
The first phase cycles through the following attack pattern:
- Hover Charge x2
- Charging Servants
- Hover Charge
- Horizontal Blood Charge
- Hover Charge
- Charging Servants