Harpy

Harpies are flying enemies added in the 1.0.4 patch. They spawn at high altitudes, typically between the height of Floating Island and the top of the map. There are blue and red winged varieties and they fire projectiles in volleys of three.

Harpies can spawn in both day and night.

The Harpy monster uses the obvious Flying AI but with a twist. Instead of ramming into the target like a Hornet would, the Harpy flies around its target and shoots out 3 projectile feathers while also actively trying to ram into the target as well. These feathers cannot be deflected with a weapon and take moderate damage (16 damage with full Molten Armor). When it rams into the player the damage is slightly less (11 damage with full Molten Armor). Because the feathers cannot be stopped with a weapon, this might explain why the feathers do not go through walls, as the feather is destroyed on contact with any block.

There can be up to 6 Harpies attacking you at once. They tend to eventually group together in 1 single bunch if left alive, probably a bug with its AI. This makes it seem like it unleashes an endless fury of feathers at you.

When killed, the Harpy's body is destroyed leaving nothing but its wings on the ground.

The Harpy seems to not drop anything other than 1-2 Silver Coins and a few Copper Coins.