BakuExo-Skin is a series of Bakugan. Four were released. They are Avior, who has a rough outside and Rubanoid who has a texture less outside. The trait that defines these Bakugan as a BakuExo-Skin Bakugan are its texture on the outside. Scaboid and Damakor might be a part of BakuExo-Skin, because it looks like they have a rough outside.