All three of Medusa's starting outfits came with their own masks. However, since nobody is going to stop him from mixing and matching parts of his outfits, he simply gets into the habit of wearing one mask at a time.
His default mask is more like a helmet or a glowy fursuit head modeled after a kitsune mask. The "face" is lit by LED lights, and he can see out of the black part of the visor. There are two gaps in the attached balaclava that covers his head and neck: One in the back to thread his hair through (he usually keeps it in a high ponytail) and one under his chin for ventilation. He lets two strands of his hair stick through this opening, and could, in theory, slip food or drink under it if he lifts his mask up a little. It looks a bit clumsy in practice, though.
Mask A
His default mask is more like a helmet or a glowy fursuit head modeled after a kitsune mask. The "face" is lit by LED lights, and he can see out of the black part of the visor. There are two gaps in the attached balaclava that covers his head and neck: One in the back to thread his hair through (he usually keeps it in a high ponytail) and one under his chin for ventilation. He lets two strands of his hair stick through this opening, and could, in theory, slip food or drink under it if he lifts his mask up a little. It looks a bit clumsy in practice, though.