Belfly

"Thin wings hide a highly volatile belly. Will give its own life to protect its territory. An angry creature with no regard for its own life. A creature without fear... can it truly be called "prey"?"

Belflies are enemies in Hollow Knight. They are quick, highly volatile flying creatures who dive at prey with no sense of self-preservation.

Behaviour and Tactics
Hangs from a ceiling, emitting a high-pitched squeak. Listen carefully for this sound as it is usually found in dark or secluded places, where spotting it usually means that it is too late to avoid contact with it.

Upon seeing the Knight, it emits a louder shriek, exposes its glowing belly, and then swoops down on the Knight, exploding on contact, dealing two Masks of damage.

Its homing is limited to a wide arc about 90 degrees below it, after which it continues in an arc until making contact with either the environment or the Knight. Dodge away when it dives in and let it explode against the surface it impacts. The blast also instantly kills any enemy in its area of effect.

It is possible to kill it before it dives as it dies in one hit even with the un-upgraded Nail; however, timing and spacing this is difficult. The Longnail and Mark of Pride Charms both make this easier. Spells, Nail Arts, and the Grubberfly's Elegy Charm can be used to dispose of it from a distance. Minion Charms, such as Weaversong, Glowing Womb, and Grimmchild, can also attack them when they are idle and safely dispatch them.

If a Belfly kills itself, it still counts towards its Journal entry.

Location
Belflies can be found mainly in the Royal Waterways and Kingdom's Edge; however, they can also be spotted in smaller numbers throughout the City of Tears, in the north part of Ancient Basin, and the Resting Grounds. Belflies are also in the Colosseum of Fools, during wave 6 and 7 of the Trial of the Conqueror and wave 4 of the Trial of the Fool.

Trivia

 * Though the timing is difficult, the Dream Nail can be used to push Belflies away from the Knight and avoid taking damage.
 * Belflies do not drop their shell if they are killed before reaching the ground.