If you have them already, or once you do, you can transfer them over to Pokemon Let's Go to use in the Kanto region. The revelation that Eevee could have bangs and Pikachu could rock a bouffant curl very much broke the internet, but that hasn't stopped me wanting to give my personal Pikachu a new do. Pokemon Let's Go is more similar to Pokemon Yellow than Red or Blue.
In Pokemon Sun and Moon you could simply head to a hair salon to change your hairstyle, or change your Pokemon's look (or more specifically, your Furfrou's look), the ability to change your Pokemon Let's Go hairstyles is nearly an Easter egg in itself. To get Squirtle for free, you need to have at least caught 60 Pokemon. There are 20 different GO Parks in the game, and each can hold up to 50 Pokemon - meaning you can transfer up to 1000 Pokemon.
Boot both Pokemon Go on your phone and Pokemon Let's Go on your Switch.
So with all that in mind, here's how to get all the Pokemon Let's Go hairstyles for Eevee and Pikachu.
Now choose the Pokemon you want to send, and select Yes when you are prompted. All players will have the opportunity to capture the Mythical Pokemon Meltan via a new Special Research quest.
Then scroll down and tap Nintendo Switch, and then Connect to Nintendo Switch. Take control in Let's Go on the Switch and head to the GO Park complex in Fuschia City. At that point switch to your phone - and because the machines are synced up there'll be a clear icon of a Switch on the Pokemon menu screen. Enter the complex and press Bring Pokemon. To qualify for a free Bulbasaur, you need to have captured at least 30 random Pokemon.