Ho-Oh appears in the sky at the end of the first Pokémon anime episode.
In “Pokémon, I Choose You!”, Ash and Pikachu see a large, colorful bird flying above the clouds after escaping the Spearow flock. Professor Oak's Pokédex cannot identify it, leaving Ash with a mystery at the very beginning of his journey.
The appearance was notable because Ho-Oh was not part of the original Kanto Pokédex and had not yet been properly introduced to viewers. The Pokémon later became one of the central Legendary Pokémon of Generation II and the mascot of Pokémon Gold.
This scene is sometimes confused with Lugia, the mascot of Pokémon Silver and a major figure in Pokémon the Movie 2000. Ho-Oh, however, is the Legendary Pokémon shown in the first anime episode, and its early appearance helped connect the original anime to the next generation of games.