Giant Bat

Giant Bat is a bigger, healthier and stronger version of the Cave Bat. It uses the same bat AI and also spawns in the cavern layer. The Giant Bat can also afflict players with the Confused debuff, causing controls to reverse. It has another version, the Illuminant Bat. It is the Hallowed version of the Giant Bat.

Like many mobs introduced in 1.1, the Giant Bat will only spawn after the Wall of Flesh has been defeated.

Trivia
This enemy, along with the Cave Bat, may be a shout-out to the Pokémon franchise; the Cave Bat is "Zubat," while the Giant Bat is "Golbat," Zubat's evolved form. In both games, both enemies are found only in caves, appear out randomly, and constantly harass the player. Also, Golbat, and occasionally Zubat as well—Zubat is less common– only appear in the higher level areas of the game, when the player has progressed far enough to get there, similar to hardcore mode, which is a higher level/difficulty than when one first starts the game.