Uxie

Uxie is a small, gray, fairy-like Pokémon with two gray tails that are each encrusted with a red gem. Uxie has a partially yellow face with another red gem encrusted into its forehead. Its head faintly resembles that of a helmet or a human brain.

Along with and , Uxie is one of the lake guardians created by . It is known as the Being of Knowledge in Sinnoh myths.

Uxie always has its eyes closed, as it can wipe out the memory of those who see them. It is both feared and respected for its ability to erase the memories of evil people. Uxie's spirit can leave its body without dying and return at will. It created all knowledge in the Pokémon universe and gave humans the ability to adapt and learn as life goes on, leading it to be referred to as the "Being of Knowledge" in the past. Notably, when Uxie first emerged, humans gained the knowledge needed to solve problems and improved their quality of life. In Pokémon Mystery Dungeon, it is shown that Uxie can create illusions. It was also shown in The Needs of the Three! (DP151) and The Battle Finale of Legend! (DP152) to be able to teleport itself, as well as other Pokémon and humans. Though it is very shy, Uxie will attack with force if it or its friends are threatened. Alongside the other lake guardians, Uxie is needed for the creation of a Red Chain, either through gems extracted from its body or through its claw. Together, they're also capable of destroying a Red Chain. They even have the power to calm down or should they be enraged, but not both at once. Uxie lives in Lake Acuity, specifically in the Acuity Cavern at the center of the lake, thus gaining its title as a lake guardian. In Pokémon Legends: Arceus, Uxie is shown to be capable of speaking human language via telepathy.

(Source: Bulbapedia)