Mostly CO2 gas (carbon dioxide), but some quantity of all of the gases that were inhaled to begin with are exhaled whether they are normal constituents of the air we breathe or contaminants of it. Also notably, the lungs of most animals are not 100% efficient at removing and using the O2 gas (oxygen) that they are designed to capture for the body's use, so some quantities of it are exhaled (less than what was originally inhaled, obviously).
Koalas are mammals and, like all mammals, they exhale air.
Mammals exhale carbon dioxide.
Mammals inhale oxygen and exhale carbon dioxide, as do all animals.
The gas removed from the body when you exhale is carbon dioxide.
The primary gas that humans exhale when breathing is carbon dioxide.
You inhale oxygen, and you exhale carbon dioxide.
carbon doxide
This gas is nitrogen.
Carbon Dioxide.
Carbon dioxide
Carbon Dioxide
Carbon Dioxide