Uxie is a legendary pokemon found in the Sinnoh region. It appears in the cave on Lake Acucity after the player encounters Dialga or Palkia. It is one in the trio of the legendary spirits. Its other counter parts are Mesprit and Azelf.
Pokedex Entry
Known as "the Being of Knowledge". It is said that it can wipe out the memory of those who see its eyes.