The Illuminant Bat is found in the Underground Hallow after the Wall of Flesh has been defeated. They serve as an underground hallow version of the Giant Bat. They are dangerous to newer players due to their high attack damage. When fighting the Illuminant Bat, it is recommended to use a broadsword weapon with high knockback, or something similar. Like all illuminant mobs, it glows, which makes it easier to prepare against. It also has a motion blur effect, just like some of the armors.