The Skubat is a ranged flying enemy found in the Sun Tower. It attacks by throwing 2 bones in an arc, which fall rapidly toward the player and pierce terrain.
A Skubat.
Skubats are essentially flying Skeletons. The main differences being they throw 2 bones instead of 1, and their tactics are different. Skubats can fly through terrain, which allows them to attack from beneath as well as safely above the player. They are more dangerous in small rooms and less dangerous in the outdoor portions of the Sun Tower.
Dispatch them quickly when they move out of terrain, or use damage over time spells to whittle them down.
There are 2 tougher versions of the Skubat called the Boobat and the Skubidydoobidyboobat.