If you could have only 1 Pokemon but have as many of that Pokemon as u like,what would it be

649 ditto's. One for each Pokemon of the Pokedex.

either poochenas or houndors

5 Pikachus. Self-replenishing electrical generator for the win.

I did something like that in my first Emerald I had boxes full of Skitty's and one in my team anyhoo I would love to have maybe Six Skitty's.

Fearow. Believe it or not, Fearows were awesome in first generation.

I'd have 1000 Magikarp XD! Magikarp army use Splash XD!

Lucario :3