Illuminant Bat

The Illuminant Bat is a Hardmode enemy. It is the Hallowed version of the Giant Bat, and is slightly stronger. It only spawns in the Underground Hallow (cavern layer under the hallow biome). Just like its name suggests, the Illuminant Bat emits a small amount of light, making it quite easy to spot. They can be very annoying to players who have recently entered Hardmode; they are rather small as enemies and have extraordinary amounts of life for bats. It is best to take them out with a ranged weapon while they are out of reach, as they can be very deadly at close range to an unprepared player.