This sound is from Bulbasaur Soundboard

Bulbasaur is a Grass/Poison-type Pokémon species in Nintendo and Game Freak's Pokémon franchise. It is a central character in the Pokémon anime, being one of Ash Ketchum's main Pokémon for the first season. It is featured in various manga, and is owned by protagonist Red in Pokémon Adventures manga.
See also: Venusaur, List of generation I Pokémon, Squirtle, Charmander, Pokémon Chronicles, and Pokémon: Indigo League.