The Eye of Cthulhu is a pre-Hardmode boss in the sandbox game Terraria. It is a giant eyeball with a long, writhing body. The Eye of Cthulhu is summoned by using a Suspicious Looking Eye. The Eye of Cthulhu is a difficult boss to defeat, especially for players who are new to the game. It is recommended that players have at least a full set of Iron or better armor and a ranged weapon before attempting to fight the Eye of Cthulhu. The Eye of Cthulhu has two main attacks. The first attack is a beam of energy that it fires from its eye. The second attack is a swarm of small, flying eyeballs that it spawns. A fanart Terraria progress bar for YouTube with Terraria Eye of Cthulhu.