A Pokemon Go player by the name of FrozenAquaCat was able to encounter a Wild Ditto while playing Pokemon Go.

He was able to force this encounter while modifying the game’s files using a Python client. Here’s a direct quote from the player:
“Through the modification of the Pokemon Go client, I was able to change the ID that shows up during an encounter from 13 (weedle) to 132 (ditto),” FrozenAquaCat wrote on the YouTube description. “The game currently crashes any time I attempt to throw a pokeball or do anything in the menu.”
He also offers this follow up video where he explains how he was able to make the Python script force the game to change normal spawns into legendary Pokemon. In the video below, you can see him spawn a wild Zapdos.

It’s really cool to see how Zapdos looks in the game. The Zapdos he spawned has a Combat Power of 753. The discouraging part is that he can’t actually catch the legendary Pokemon, maybe he needs a Master Ball. There’s still no word on how to collect a master ball.