Smoochum can wait

Unfortunately for Smoochum, You have a reputation to uphold. Right now, you have to get to Oak's lab. The starter is the mainstay in most any team, and there is a right answer. Grass types are abundant and worthless, so Bulbasaur is out of the question. Squirtle is a decent pokemon, but the game demands a water type devoted to HMs, so you'd need to choose between nerfing your starter or doubling up on a type. Additionally, with second generation pokemon in the mix, there's a different water type for you.

That leaves Charmander. There aren't that many fire types, and Magmar's the only non starter with a third tier evolution. You have to keep it out of Ash's hands.

You return your pocket nympho to her ball and hide it in your desk. You'd rather not bring her along in case anyone finds her and denies you your fire. It's not the best kept secret, but you only need it to hold a few minutes. You rush downstairs and out the door before your sister can raise any questions about your mysterious package.

Outside, you see Ash on his way to the lab, so you decide it's time to do what Gary Oak does best: manipulate Ash into making stupid choices.

"Hey Ash!" You call and wave him down. "On your way to get your first pokemon?"

Ash snort at your approach, but takes up the conversation. "Yeah, what's it to you."

"What are you picking?"

Ash stops to think, "I dunno, they're all good in their own way, I can't really weigh them against each other."

Yes! He's on the fence. Time to push him the wrong way. This will require a delicate balance of insulting Ash and praising Bulbasaur.

You laugh in his face, making sure to spit on him while doing so, "Are you really that stupid? I didn't think it was possible that I'd overestimated your intelligence, but you always manage to surprise! This is an easy choice, but here you are still mulling it over on the way to the lab! Bulbasaur is the only dual type, and it's the best with status effects. You do know what status effects are, right? Probably not. Okay, you know how you don't move when you're asleep. It's the same for pokemon. Do you get where this is going? A sleeping pokemon can't fight back against attacks or being captured. You'd definitely need the help with both. Too bad I'm taking it! You'll have to make due with one of the other starters. Have fun losing to fish with Charmander!"

By the time you reach the lab, Ash is fuming with rage. You're sure he doesn't hear any of the professor's preamble, but he snaps back to attention right at the end.

"Gary, why don't you let Ash pick first?" Oak offers

"Fine, wouldn't want the baby to cry." You hide your nervousness and play the role flawlessly. It's time to see if Ash falls for your ruse.