Nethereyes are hostile mobs that pursue the player by hovering around them. Nethereyes spawn in both the Overworld and the Nether. A Nethereye has 10 hearts, equal to the health of the player. They drop Obsidian, Netherrack, or (rarely) Bedrock.
Nethereyes are one of the three mobs (the others being the Blaze and Ender dragon) in the game with the capability to fly. When they are not attacking, they will float around randomly in any direction. When they are flying upwards, they will be forced down by gravity, so they usually do not fly too high. If they are targeting another mob or the player, they will fly towards it quite quickly.
They spawn both in the Overworld, at night, and The Nether, in which they more commonly spawn.
- Nethereyes were not based off of Terraria's similar mob, the Demon Eye
- Nethereyes are one of two hostile mobs (the other being the Enderman) that spawn in 2 different dimensions.
- Nethereyes are said to have broken out of the Nether, and this is why they drop Netherrack in particular.
- Nethereyes used to have legs and walk around. They used to be called Nether Walkers, but their name was changed after their behavior was changed.
- Nethereyes are still named "Nether Walkers" in the game's code.
- Killing at least one nethereye will give an achievement.
- Prior to the upcoming 1.23 update, Nethereyes have a problem with movement, causing them to always go the wrong direction when attacking the player. This makes finding and killing them harder, but avoiding them very easy.
- Sometimes Nethereyes glitch into or out of blocks.