https://www.polygon.com/2018/8/2/17644032/spinda-pokemon-go-countdown-theory

Spinda is now making its first appearance in Pokémon Go. The third-gen Pokémon is known for having unique patterns, and its Pokédex description says that no two Spinda have the same pattern of spots. In the original Pokémon Ruby and Sapphire, this meant that Spinda had over 4 billion possible variants.

Right now, dataminers have found only eight variants. The Pokédex entry for Spinda has eight blank circles beneath the Pokémon, one for each. Here’s the thing: They’re not available in the wild just yet; instead, like many other Pokémon, Spinda can only be obtained after completing a Field Research quest (in this case, landing three nice curveballs in a row ... get it, ‘cuz they spin?).