Gary Oak, while not the main character, could still be considered a main character. He leaves on his Pokémon journey on the same day as famed Ash Ketchum, although a bit before him, since Ash managed to oversleep. He shares the same goal as Ash does—to become the world’s leading Pokémon Master. And, judging by the huge crowd of onlookers, and the group of beautiful cheerleaders that follow him around, it seems as if he has a good chance of succeeding!

He is the grandson of Professor Oak, the world’s leading authority on all things having to do with Pokémon. And as such, you can tell he has spent a lot of his own life studying Pokémon, and he displays this in the “Dig Those Diglett!” episode, as he slips into his own personal Pokédex mode.

Always being ahead of Ash, Gary has collected ten Kanto badges before Ash earns his eighth. He also has over two-hundred Pokémon including Nidoking, Nidoqueen, Arcanine, Dodou, and Eevee—which later evolves into an Umbreon. Gary’s Umbreon is the first seen in the series, to my knowledge, since Ash seems to have never seen one.

In the beginning of the series, Gary seems to be very arrogant. He disses Ash at every meeting, and even writes “Gary was here, Ash is a loser!” on a road sign. We see him every so often, and once in a while, Gary even tries to help Ash out. One instance of this, is when Gary saved Ash’s life inside Viridian City Gym, when Meowth was about to blow up the podium he was standing on.

Over time, Gary seems to calm down a bit. He even congratulates Ash after their first battle, telling him he and Pikachu did a great job, even though he and Eevee defeated them. Also, the cheerleaders have disappeared. Gary makes a few more appearances, but they are all spread out, and most only last for a few seconds. But, with the number of times he’s mentioned, Gary still makes a very big impact on the show.

I do know that Gary’s pokemon are:

nidoking

nidoqueen

arcanine

eevee/ umbreon

krabby

doduo
everyone always forgets the krabby, but it’s seen in the episode with bill at the light house, when ash calls professor oak to see how his krabby is doing, prof. Oak tells him that he has a puny krabby, then he shows him the krabby that Gary caught which is like twice the size of ash’s. He also seems to be a more responsible trainer ever since the johto journeys, and he must be if eevee was happy enough to evolve to umbreon for him. Thas all i know on Gary, other than what was already mentioned.