Avian is a recurring enemy classification in the Hyperdimension Neptunia series. Enemies under this classification have been present since the first Hyperdimension Neptunia, but there was no proper name until Hyperdimension Neptunia Victory. As the name implies, Avian enemies are essentially bird type enemies. However they do not necessarily need to be able to fly to be considered Avian. Many monsters such as the Cardbird enemies remain on the ground at all times but have wings.