From Source:

So I asked my Twitter what Pokémon I should draw a while ago, and I got a result of doing this- I barely recognized the ones they suggested, and most of them I didn't know existed, since I haven't touched a single Pokémon game in almost a decade. I don't know much after the 5th generation, but even at that I'm at a loss. if I'm being honest with myself, I'm most familiar with up to the 2nd generation, since I remember myself playing Pokémon Silver on the Game Boy Color. So the next time I draw another one of these as a picture, animation or something similar, I'm most likely going to ask my twitter again, because learning Pokémon while I do stuff like this is honestly pretty fun.