With the fifth generation of Pokémon monsters introduced (in North America) earlier this month, the bestiary is up to nearly 650. That’s a lot of Pokémons, and it figures not every one of them is recognised as much as, say, Charmander, Snivy, Pikachu and, yes, Mudkip.
A series of five surveys, four with extremely large sample sizes – more than one million have taken the Generation I recognition quiz on Sporcle, have effectively pegged the least recognisable Pokémons. Generation V has been taken 1,976 times, the least of all five. But according to the results, these are the five most-forgotten Pokémons across all five generations, in descending order:
Generation I: Marowak, 36.7 percent; Kingler, 35.4 percent; Lickitung, 33.7 percent; Exeggcute, 31.4 percent; Exeggutor, 31.1 percent.
Generation II: Slugma, 37.1 percent; Shuckle, 35.9 percent; Magcargo, 34.3 percent; Qwilfish, 34 percent; Corsola, 33.9 percent.
Generation III: Chimecho, 41.3 percent; Crawdaunt, 41.1 percent; Corphish, 41.1 percent; Whiscash;, 39.2 percent; Barboach, 38.8 percent.
Generation IV: Finneon, 38.1 percent; Lumineon, 37.9 percent; Chingling, 37.4 percent; Chatot, 37.1 percent; Mantyke, 36 percent.
Generation V: Accelgor, 20.6 percent; Stunfisk, 20.5 percent; Elgyem, 17.7 percent; Amoonguss, 16.6 percent; Beheeyem, 15.6 percent.
Accounting for Generation V’s low scores being because the game is so new in the West, it’s still pretty good when your least recognisable characters are still recognised by 300,000 out of a million people.
It’s also a little funny that Exeggutor is the least recognised out of the oldest generation. Tsunekazu Ishihara, president and CEO of The Pokémon Company, said in 2000 that Exeggutor was his favourite. “That’s because I was always using this character while I was debugging the program.”
GamingHUD Archive 
In all honesty, I stopped caring after the first 150. How many leaf/reptile combos can we have? lol
There are no pokemon after 150. The rest are a lie. A dirty lie!