Latias is a Pokémon with a birdlike body stylized after a plane. Its long neck stretches forward from its squat body. It has no legs, usually floating instead. The rear half of its body is largely red and the upper half white, with jet-plane wings high on its rear and fins on the bottom near its tail. A blue triangle marks the center of its chest, while a red mask partially covers its face. Ear-like fins sit on top of its head and its eyes are yellow. It has short, three-fingered arms with a red covering on the outer side of the lower arms. Latias is a female-only species, with being its male counterpart.

Latias ruffles its feathers and cries loudly when there is hostility toward it. Its glass-like, downy feathers can enfold its body and refract light, which allows it to become invisible or alter its appearance. It is highly intelligent and can understand human speech. It is capable of using telepathy to communicate with others. In the fifth movie, Latias had the ability "Sight Sharing", which allowed Latias and people around it to see exactly what Latios was seeing. It normally does not make contact with humans or other Pokémon and disappears when an enemy is nearby. It forms herds with several members and is usually found near water. Latias loves Latias Treats made by Snacksworth, who once encountered it in the past. Latias can be summoned by the Eon Flute.

Forms
Latias can Mega Evolve into Mega Latias.

As Mega Latias, the red parts of its body change to purple. Horns grow from the side of its head and run along its jaw. It loses the wings on its back and similar but larger wings attach to its lower arms, normally held in a level position. Triangle shapes now mark the forward point of its wings instead of its chest.

(Source: Bulbapedia)