Parakeets

I believe Gengar can learn Thunderbolt. Coupled with his speed and high special attack Squirtle and Wartortle lose.

BAM.

Nice try. Good effort. I would have admitted defeat had I not remembered that Squirtle and Wartortle can both learn Gyro Ball, so your speed advantage will only lead to your downfall. Both pogeymonds can also learn Zen Headbutt, which will inflict 2x damage to your Gengar, especially since both pogymands have super hard heads. Without awesome defensive moves like Protect, Iron Defense, and Withdraw, your fail thunder attacks will be useless.

Nice try, but Gengar shall never beat such awesome turtles.