>>48030571It's some kind of evolutionary holdover that stores power ready for Cherubi to evolve
>Diamond: The small ball holds the nutrients needed for evolution. Apparently, it is very sweet and tasty.Pearl: Sunlight colors it red. When the small ball is drained of nutrients, it shrivels to herald evolution.
Platinum: The small ball is not only full of nutrients, it is also tasty. Starly try to peck it off.
HGSS: It evolves by sucking the energy out of the small ball where it had been storing nutrients.
>Sword: It nimbly dashes about to avoid getting pecked by bird Pokémon that would love to make off with its small, nutrient-rich storage ball. >Shield: The deeper a Cherubi's red, the more nutrients it has stockpiled in its body. And the sweeter and tastier its small ball! 
