The Big Sightseer is a Hardmode enemy which spawns in the Astral Infection biome. It slowly pursues the player in an attempt to ram them, occasionally firing a projectile with a double-helix trail. It will emit dust from its mouth shortly before firing, telegraphing the attack. The projectile harmlessly bursts upon contact with tiles or any weapon.
- The hurt sound for this enemy is very similar, if not the same, as the hurt sound of Alcoons from SNES game Super Metroid.