Sylveon (Japanese: ニンフィアNinfia) is an unknown-type Pokémon and also an evolution of Eevee. More information about the Pokémon is currently unknown.
Sylveon is a Pokémon with cream coloured fur on most of its slender body and a reddish tail. There are two bow shaped and scarf-like objects around its body. It has four legs, each one a pink color - like the tail - and three toes on each. It also has two large blue eyes and long pink ears.
Like the other Eeveelutions the name might give us some clues for his element because:
In the English name "Sylveon": The “Sylv” part of the name seems to refer to a Sylph. In the occult philosophy of Paracelsus, a Sylph is a class of imaginary beings assumed to inhabit the air.
In the Japanese name "Nymphia": They seem to obviously be based on a Nymph from Greek and Roman Mythology. Nymph are often depicted with wings; flying around like fairies. A Pokemon based off a Nymph or Fairy is probably going to be Flying Type.