Back in 2014, Google and The Pokémon Company collaborated on an April Fool's joke that had massive ramifications for the IP. On that day, Google Maps users could see Pokémon in certain locations. This would eventually lead to the release of Pokémon Go, one of 2016's biggest releases. Now, Google and The Pokémon Company are working together again.
As per VGC, if you head to the Google app, and search in any of the names of the original 151 Pokémon, you'll be able to try and catch the pocket monster to add it to your PokeDex. The game is very simple, and doesn't appear to have any bonus for catching all of the Pokémon, but it's a neat way to idle away some time.
It appears that this only works via the Google mobile app, as we couldn't catch any Pokémon from a quick search in the browser. Each time you grab a new Pokémon, you'll be given a hint to find another, eventually bringing you to all 151 if you keep going.