Ultra-sun: It can’t help but hear a pin drop from over half a mile away, so it lives deep in the mountains where there aren’t many people or Pokémon.Moon: According to tradition, people who see a pair of Clefable skipping by can look forward to a happy marriage.Alpha-sapphire: Clefable moves by skipping lightly as if it were flying using its wings. Its bouncy step lets it even walk on water. It is known to take strolls on lakes on quiet, moonlit nights.
Prof. Lotus' Notes: Clefable is unofically referred to as an Extraterrestrial Pokémon. This link is strengthened by Clefairy needing a moon stone to evolve.