Swirlix is a small, fluffy white Pokémon with two pink spots on the top of its head. It has a small pink nose in between its two eyes, which have pink sclera and a white pupil. The lower half of its body is light pink, and its tail is pink with some white near the base. Its mouth is covered with the fluffy substance that covers the rest of its body, and its pink tongue is constantly sticking out. When it opens its mouth, two pointed teeth can be seen just below its upper lip. Its feet are rarely visible; when they are, they are seen to be a light shade of pink. It can entangle its opponents with white sticky thread. It only eats sweets, which makes its fur as sticky as cotton candy.
Swirlix appears as a Poké Ball summon in both versions of the game. It uses Cotton Spore to slow down nearby opponents.
NA: Swirlix, a Fairy-type Pokémon, has a serious sweet tooth. However, all those sweets make its fur really sticky. If you trade a Swirlix while it holds Whipped Dream, it'll evolve into a Slurpuff. In Smash Bros., Swirlix likes to use Cotton Spore. Getting hit by this attack will seriously slow you down.
PAL: Swirlix has a serious sweet tooth - it eats so many sweets that even its fur is sticky and sweet. Not that you should try eating its fur. In this game, it'll use Cotton Spore to slow down all of the other fighters. See? Definitely not edible. Fun fact: if you trade Swirlix while it's holding a Whipped Dream, it'll evolve!
Swirlix is based on cotton candy, previously known as fairy floss (a name still used in Australia), which may be the inspiration for its type. The way Swirlix entangles foes in its sticky threads may be a reference to European folktales in which eating fairy food traps mortals in the fairy realm. Considering its lolling tongue, nose, ear-like circular "bumps" on its head, and its tail, it may also be based on a dog, more specifically a Bichon Frise or poodle. Its white body and pink, ear-like bumps may also reference folk beliefs that one can distinguish a fairy dog by its white fur and red ears.
Swirlix may be a combination of swirl and a corruption of licks.
Peroppafu may be a combination of ペロペロ peropero (onomatopoeic sound for licking) and puff.