"Which Pokémon are hardest to find?"

Just wondering what people think are the least common or hardest Pokémon to find. Like how Pokémon like Magikarp, Psyduck and Zubat are found in almost every game, which ones are found in the wild in the fewest games (not counting legendaries/mythicals and event only mons obviously)?I know you can catch everything available at the time between XYORAS, but is anything just straight up easier to obtain by transferring from Gen III or IV?Thought of this when looking up Skuntank. In the 17 games released since its debut in Gen IV, it's only found wild on 2 routes in Diamond, and Stunky's only found in Diamond, Hidden Grottoes in Black 2 and Route 11 in XY! So both Stunky and Skuntank are incredibly uncommon.I'm thinking Pokémon like Claydol, Chimecho and Lumineon will belong here, since to me they don't seem very common, but I'll go look some more up. What does everything think? via /r/pokemon http://ift.tt/2lgPia3