How about an [egg](https://bulbapedia.bulbagarden.net/wiki/Pok%C3%A9mon_Egg), also seen from above?  Does that count?

[![Togepi and Elekid eggs touching][1]][1]


In the anime, a [Sandshrew](https://bulbapedia.bulbagarden.net/wiki/Sandshrew_(Pok%C3%A9mon)) appears to be able to roll up into a uniform sphere: https://www.serebii.net/anime/characters/aj.shtml

[![AJ's Sandshrew rolled into a ball with three Ratata looking at it][2]][2]


Also mentioned in the episode is [Electrode](https://bulbapedia.bulbagarden.net/wiki/Electrode_(Pok%C3%A9mon)):

[![Electrode image from Pokémon Go!][3]][3]

[Munna](https://bulbapedia.bulbagarden.net/wiki/Munna_(Pok%C3%A9mon)) might look circular from the right angle:

[![Munna][4]][4]


  [1]: https://i.sstatic.net/aE0cD.png
  [2]: https://i.sstatic.net/QUCco.png
  [3]: https://i.sstatic.net/NNgan.png
  [4]: https://i.sstatic.net/QCpzo.png