Purin

Purin is a pink Pokémon with a spherical body. It has pointed ears with black insides and large, blue eyes. It has small, stubby arms and slightly longer feet. On top of its head is a curled tuft of fur. Its body is filled with air and, as seen in Pokémon Stadium, Purin can deflate until it is flat.

Purin can use its eyes to mesmerize opponents. Purin has a large lung capacity, exceeding most other Pokémon. Once it has an opponent's attention, it will inflate its lungs and begin to sing a soothing and mysterious lullaby. This melody can cause anyone who listens to become sleepy. If the opponent resists falling asleep, Purin will endanger its own life by continuing to sing until it runs out of air. It will continue to sing until opponent is asleep. It is able to adjust the wavelength of its voice to match the brain waves of someone in a deep sleep. This helps ensure drowsiness in its opponents. Its vocal range exceeds 12 octaves, but its skill depends on the individual. Its song varies by region, and in some areas, it sounds like shouting. Purin can mostly be found in lush green plains and grassy meadows.

(Source: Bulbapedia)