Reversible Poké Ball plush

A number of different plush figures have been released that can be changed from a Poké Ball to a Pokémon, the exception being, which changes into an Egg.

Quick-Change Poké Ball
Quick-Change Poké Ball was a set released by Hasbro.

Pokémon Diamond and Pearl Plush Collection
Released by Tomy Yujin Europe (TYE).

Jakks Pacific sets
These plush figures are merchandise for and were released by Jakks Pacific.