Lugia is a dual-type Psychic/Flying legendary Pokémon. It is not known to evolve into or from any other Pokémon.

It is often considered to be closely related to Ho-Oh, even sometimes as its polar opposite. Silver represents Lugia as "guardian of the seas," and Gold represents Ho-Oh as "guardian of the skies." Lugia (Japanese: ルギア Lugia) is the main character of the movie, The Power of One. Its Japanese voice actor is 山寺宏一 Koichi Yamadera and its English voice actor is Eric Rath.

In the movie, Lawrence III wanted to capture Lugia. In order to accomplish his goal, he set out to enrage and capture the legendary birds. By doing this, Lugia was prophesied to appear to calm them. His plan was then to capture Lugia for his "collection."

Although he ended up injuring it, Lawrence III did not succeed in capturing it. With the help of Ash, Lugia was able to stop Lawrence III and calm the birds before the unbalance caused destroyed the world.

Lugia was briefly mentioned in The Mystery is History by Ash and James when they encounter Silver for the first time. Whether this makes the movie canon is unknown.

Lugia communicated with humans through telepathy, much like Mewtwo.

In The Mastermind of The Mirage Pokémon, it was seen in Pikachu's memories.

(Source: Bulbapedia)