Paimon is a non-playable character in Genshin Impact and accompanies the Traveler throughout their adventure in Teyvat as their guide. She met the Traveler by being fished out of a lake in which she mentions she would've drowned if not being fished out. She is currently representing Genshin Impact as it's mascot, being on the face of the Genshin Impact app, website, and social media icons.
(Source: Genshin Impact Wiki)
