Corruptor

The Corruptor is a hardmode enemy similar to the Eater of Souls, but are much stronger, having 230 health each.

Their projectile attack will corrupt the ground it touches, so its advisable to slay any chasing you out of the corruption to avoid losing any Hallow you have in place to contain the corruption, as well as fight Corruptors in close range so they do not use their ranged attack. The Corruptors Vile Spit doesn't make corrupted grass grow on dirt, but can only convert any kind of grass into corrupt grass, except for Mushroom grass. Their Vile Spit can also inflict the Weak debuff for a very long duration. As with Fire Imps and Dark Caster, the Vile Spit projectile they fire is an enemy with one health, meaning you can destroy it with any kind of weapon. This also means that by effect it will sometimes block shots from non-piercing projectile weapons.

Behavior
Corruptors will behave similarly to the Eater of Souls, albeit they (usually) do not attack in swarms. They will use a ranged attack only if the player is not attacking from close range. Because of this it is advised to fight them in close range to prevent unintended spreading of the Corruption. Provided you have already stopped the spreading of Corruption on the ground, you can also build a wall that will block any missed Vile Spit so that it will not hit any non-Corrupted regions behind the battle site.