Pokemon Go - Secret 4th Starter Pokemon!!
Looks like there's a way to get yourself a 4th starter Pokemon! Say "bye" to Bulbasaur, Charmander, and Squirtle and welcome this little fella!
After talking to Professor Willow and he offers up the original 3 starter Pokemons, all you have to do is run away from them, literally. You're going to have to get out there and run OR you can hop in a car and drive off. After you've driven/run a certain distance away, the 3 Pokemons respawn at your location. Then run/drive away again. After they've respawned for the 4th time, you'll see an additional 4th Pokemon appear and you can then capture it!
Happy hunting!