Latias is a Dragon/Psychic-type that appeared in Pokémon Heroes.
Latias and her brother, Latios, lived in the Secret Garden in Alto Mare, where they were the guardians of the Soul Dew. They were friends with Lorenzo and Bianca.
Latias and Latios presented some very unique powers in the movie, such as sight-sharing, invisibility and shapeshifting. They are also very fast and cover wide ranges in terms of orbits, and rather patient and tenacious. Other than that, this Latias and her brother mainly tackle to fend off enemies, or to emit powerful, protective fields of light that can be enhanced even further in cooperation when they are forced to do so. However, in contrast to her brother's attitude, Latias is rather afraid of fighting with larger enemies, and tend to take a distance from foes (dislikes of conflicts and battles are common among the sibling). However, based on her behaviors seen in the movie, she could have get used to the urgent situation as the time passed.
Latias commonly shapeshifts to appear the same as Bianca, and befriended Ash under her persona. She may have a crush on him as well, as was hinted in the movie, undoubtedly because he saved her from Annie and Oakley.
In The Mastermind of Mirage Pokémon, she was seen in Pikachu's memories.