The Head of Cthulhu is a very powerful War Mode boss summoned with the Gory Brain during the night. If it is not summoned during the night, nothing will happen. Once summoned, a message will appear: "You have angered the lord of the Ground... The Head of Cthulhu will begin attacking shortly.
Phase 1
Phase 2 
(minion)
(Total credits to TerrariaFanSpriter for the gif Click here to see His page.)
Stats[]
The body of the head (unlocked in the second stage) has 145,000 
and each eye has 73,000 .
First stage[]
In the first stage of the fight, the Head of Cthulhu will orbit the player, spawning Servants of Cthulhu and Creepers in very large numbers. If it makes contact with the player, which it will try to avoid by teleporting, it strikes with 250 melee power. It will fire lasers at the player from its red eye and Cursed Flames from its right and has 380 ranged power.
Second stage[]
The second stage of the fight is unlocked when the Head of Cthulhu's eyes are brought down to 25.000 . They will then detach from the head, which will keep spawning Creepers, although it will not spawn Servants of Cthulhu. The eyes will avoid the player and get 500 attack power.
The main head becomes vulnerable in this stage. It has 50,000 .
Third stage[]
The third stage of the fight is unlocked when the Head reaches 25,000 and the eyes are defeated. In this stage, the Head of Cthulhu will begin flying at the player while shooting very high speed lasers with 200 power. If it makes contact, it strikes with 700 melee power.
Drops[]
Head[]
- 5
(100%) - 50 (100%)
- 150-200 Watery Tissue (100%)
(100%)
(100%)Only one of the following will be dropped
- Tide Charm (33.3%)
- Cthulhu Chain (33.3%)
- Cthulhu Broadsword (33.3%)
Green eye[]
- 25 (100%)
- 15-30 Souls of Sight (100%)
- Cursed Flamethrower (10%)
Red eye[]
- 25 (100%)
- 15-30 Souls of Sight (100%)
- Laser Antenna (10%)