Spending too much time staring at your Pokédex wondering why you can't find so many of those empty silhouettes? Maybe they're just too rare for you to capture. Here to lend a helping hand, Youtub-er Ali-A counts down his own list of the 10 rarest Pokémon.
The most useful part of the list is it gives a nice look at how to capture the ones that are within reach and maybe some reasons why you haven't been able to find that Mr. Mime you want so badly.
It can be hatched through a 10km egg, which isn't the easiest way to get a Pokémon, but if it was easy it wouldn't be on this list. Maybe take up walking dogs at your local shelter to help you get there.
Here's another that can be hatched from a 10km egg, but is a little harder to find in the wild. If you do find one, good for you. It's a nice one to take down the street to the gym.
Gyarados requires 400 Magikarp candies to evolve, so you'll have plenty of opportunities to save up your best CP Magikarp for the evolution, ensuring that your Gyarados is truly a boss.