Wraith

Wraiths are Hardmode ghost-like enemies that can travel through blocks. They can inflict the Slow debuff, and have glowing red eyes that are visible even in complete darkness. They spawn at the surface layer at night.

Wraiths appear to be flying, however within empty space they can only hover slightly off the ground. They can only fly upwards when they have foreground blocks to "swim" through.

Wraiths are immune to the Poisoned, On Fire!, Cursed Inferno and Shadowflame debuffs.

Tips

 * Any structure raised least 7 tiles above the surface will prevent a wraith from levitating up and through it.