It has gills. The Wallobus has gills to get oxygen. These gills protrude from the body surface, and contain extensions of the vascular system. The gills contain lots of blood. As the water flows by, oxygen is absorbed into the blood.
Oxygen diffuses into the capillaries while the carbon dioxide diffuses the other way.
To transport the oxygen efficiently, the Wallobus uses veins. It also uses these veins to transport its fuel and building blocks around. The veins are an important part to the Wallobus. To withstand the huge temperature changes, the Wallobus has excess fat to keep it warm when the temperature is cold. When it is warmer, it will shed its fur allowing its body temperature to go down.