The Barreleye is a species of fish that lives in the deep sea. Its large, green eyes are contained in a glass-lie structure on the top of its head, with the two, black, eye-like dots on the front of its head actually being nostrils. It is able to move its fins so little that it can stay near perfectly motionless. It can rotate its eyes vertically and horizontally to see all around it. It is theorized that the glass-like casing on its head protects it from the stinging tentacles of the giant siphonophore, allowing it to steal prey from the dangling tentacles.