It takes balls to approach a random member of the opposite sex and try to acquire their phone number. To do it dressed as Ash, Brock, Misty, and Team Rocket? That takes Master Balls. Sorry.
"I will be your Nidoking, you can be my Nidoqueen" might be the sweetest Pokémon pickup line possible. It's all downhill from there, from "I would love to Squirtle all over your face" to "you just made my Weedle use String Shot".
I hope I don't have to warn you that using any of these is an incredibly bad idea. If you really want to pick up a date, stalk them until they notice you, and then run away. They'll find it utterly charming.
Pokemon Pick Up Lines - Get Her Number! [YouTube]