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A pink Rhyhorn eating a Pinkan Berry
A Pinkan Berry (Japanese: ピンカンのみ Pinkan Fruit) is a type of Berry that is only found on Pinkan Island of the Orange Archipelago. They were first seen in In the Pink.
The Berry has special properties, as it will turn any Pokémon that eats it pink. If a Pokémon eats the Berries often enough, the color change will be permanent; however, if it is only eaten a few times, the Pokémon will soon revert to its normal coloration. When Ash's Pikachu ate the Berries, just the tip of his tail and his cheeks turned pink, rather than its whole body.