Gary Oak

Gary Oak is Professor Oak's grandson and Ash Ketchum's rival in the first few seasons. His starter Pokémon was a Squirtle that later evolved into a Blastoise.Gary has auburn hair and black eyes. In the original series, Gary wore a long-sleeved purple shirt, a black necklace, dark blue pants and boots. In the Advanced Generation series and Diamond and Pearl series, he wears a black collared shirt, purple pants, a black necklace with a lavender bead instead of the original gold one, and black sneakers with a dark backpack.The day he started out on his Pokémon journey, Gary came off as an arrogant Trainer, much like his game counterpart, Blue. His chosen starter Pokémon was Squirtle, which was actually the same Pokémon that Ash originally wanted to start with. He even had a group of cheerleaders who cheered him on in all of his battles and would go so far as crying whenever he lost. He didn't walk on his journeys like most Trainers did; instead he had his own sporty red convertible with a chauffeur. Gary loved when he got a chance to make fun of Ash by bragging about how far behind Ash was compared to him. He also gave Ash the pet-name of "Ashy-boy" (Japanese: "Satoshi-kun"), which occasionally seems to annoy him. His style of training at that point was to capture many Pokémon and to use the strongest, as a stark contrast to Ash, who was more focused on developing a bond with his Pokémon.

His arrogance continued overtime during Ash’s journey in Kanto until he challenged the Viridian City Gym Leader, Giovanni, to a Pokémon battle for his final (but not necessary) Badge in The Battle of the Badge where his team was brutally defeated by Mewtwo. However, this still didn't change his arrogance. It would take a loss at the Pokémon League way later on against Melissa for Gary to finally realize that he greatly needed to change himself.

In his few appearances during the Johto saga, Gary seemed to have become the complete opposite of who he was. He became much more polite and respectful to others, including Ash