Clinker

Clinkers are large, brown, amoeba-like creatures of questionable composition that block the ventilation grates in Clinker's Cavern of Grunty Industries. Banjo and Kazooie are tasked with clearing twenty of them out in a limited amount of time before the area becomes toxic. (Clinkers can still be cleared after the air is infected but it is a risky and dangerous maneuver.) Clinkers are easily found due to the constant annoying sound they make.

If Banjo inputs the cheat "HONEYKING" in the Code Room of Mayahem Temple, the Clinkers cannot harm him even after the timer has expired; he will just have to deal with the limited visibility of the toxic, greenish gas.

Trivia

 * The Clinkers are named after the British slang term "clinker", which is a deposit of rust and grime that tends to form on various metallic surfaces. However, it is unknown if the Clinkers in Banjo-Tooie are composed of said material or not.
 * Some people believe that the Clinkers are somehow related to the Great Mighty Poo in Conker's Bad Fur Day. However, this has yet to be confirmed.