From Bulbapedia, the community-driven Pokémon encyclopedia.
Camomile Island (Japanese: カモミール島 Camomile Island) is an anime-exclusive Island found in Kanto.
The island is mostly a Pokémon reserve that contains many different species of Pokémon within its grassy plains. It contains a Pokémon Center that is run by Nurse Joy. She is able to get around the island in a SUV.
When Ash and his friends arrived on Camomile Island by boat, Ash's Donphan tried to play with a grass ball with a herd of baby Rhyhorn; however, its size made them cry and triggered the adult Rhyhorn to stampede. Luckily Nurse Joy was able to come to the rescue with her Meganium, who calmed down the Rhyhorn with Growl. As Brock fell in love with Nurse Joy, Ash's Grovyle battled a wild Tropius, causing Grovyle to become badly wounded.
While Team Rocket was trying to capture Tropius, Grovyle was healed by Meganium, making him blush and begin to fall in love with it. When Team Rocket tried to capture Meganium in the middle of a second battle between Tropius and Grovyle, Grovyle manages to pull off a win. During the battle, Meganium destroyed Team Rocket's mecha and rushed towards Tropius. As Grovyle sees the love between the two Pokémon, he becomes heartbroken. Suddenly, Grovyle evolves into Sceptile. Unfortunately, the heartbroken Sceptile is unable to use any of its attacks as it tries to use Leaf Blade.
Pokémon seen on and around the Island
There is an abundance of Pokémon living on the reserve.