A Link to the Past
Chasupa first appear as Link makes his way through the Hyrule Castle Tower in the Light World. They are nearly identical to Keese in that they stay perched at a certain location until Link draws near. Once Link comes close, the Chasupa starts to fly around the room, aggressively pursuing Link before landing at a specific point. There is virtually no difference other than physical appearance to the Keese that appear in the game. Like Keese, Chasupa take just one slash from Link's Sword or one shot from the Boomerang to defeat.
A Link Between Worlds
Much like in A Link to the Past, Chasupa can be found in the Caves of Lorule as a counterpart to Hyrule's Keese. These enemies are located mostly in Caves, often in places where battling them can be dangerous due to the precarious surroundings. They can be defeated easily with the Sword.