Venusaur was featured on the cover of the original Japanese Green version of Pokémon.
Pocket Monsters Red and Green were the first Pokémon games, released in Japan for the Game Boy in 1996. Their cover mascots represented two of the game’s three final starter evolutions: Charizard appeared on Red, while Venusaur appeared on Green. Blastoise later became the cover mascot associated with the Japanese Blue version.
International releases changed the arrangement. The games were released outside Japan as Pokémon Red and Blue, so many players grew up seeing Charizard and Blastoise on the classic package art. The original Japanese Green version was not released internationally in its original form, which is why its Venusaur cover is less familiar to some fans.
Venusaur is the final evolution of Bulbasaur and Ivysaur, and it is a Grass/Poison-type Pokémon in the first generation. The cover choice also helped establish the tradition of using a prominent Pokémon as a visual symbol for each paired version.