Klang is a Pokémon resembling three interlocking gears, with six teeth on the smaller two gears and eight teeth on the larger gear. The teeth of the smaller gears are a light gray, while their central regions are much darker. The teeth of the larger gear are a medium gray and its central region is darker. The left eye of the smaller gear is a white "X", while its right eye has a black pupil and a white sclera. It has a round green nose and a small mouth that is wide open. The large gear appears to have a face with a black square for its right eye, a black circle for its left eye, and a sharply angled white frown.
Klang can fire tiny gears at high speeds. Klang and its evolutionary relatives are the only known Pokémon capable of learning the move Gear Grind. Prior to Generation VII, Shift Gear was also one of its signature moves. When it gets angry, its gears rotate faster. Klang communicate with each other by spinning their gears in different directions. Klang is often chosen as a logo for many companies in Galar. Klang is believed to be the symbol of industrial technology.
Klang debuted in White—Victini and Zekrom and Black—Victini and Reshiram alongside Klink and Klinklang; they are all under the ownership of Mannes. He used the three for various tasks, such as powering the music machine at Eindoak Town's Harvest Festival, doing yard work on his property, and powering his helicopter in the climax of the films.