Air bubble

Oxygen is used in the Banjo Games to show how much air Banjo and Kazooie have used while under water or in polluted air. In Banjo-Kazooie, the oxygen meter is shaped like honeycombs. In Banjo-Tooie and Grunty's Revenge, the oxygen meter is shaped as bubbles. If Banjo and Kazooie run out of air while under water, they drown. If they run out of air in the presence of polluted air, they will suffocate.

In Banjo-Kazooie, Gloop the fish who is located at the very bottom of Clanker's Cavern, is able to give Banjo and Kazooie air bubbles. These air bubbles replenish one unit of oxygen.

In Banjo-Tooie, if Banjo and Kazooie rescue Roysten from under the boulder in Spiral Mountain, he will reward them with extra Oxygen Bubbles.