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 Badgewhere 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.
Uncle Funtime: Thanksgiving Edition Edit
Gary celebrates Thanksgiving with Ash and co. in Hingham.
School Daze 2: A Jolly Good Battle Edit
Gary watches the Regular Show finale with Ash and co.
Franklin Expeditions Edit
Though he doesn't travel with Ash in Franklin, Gary makes a few appearances in this series:
A Medical Poaching Edit
In "A Medical Poaching", he challenges Ash to a Pokemon Battle, which is interrupted by Team Rocket.
Game of Quizzes Edit
In "Game of Quizzes", he appears in a Roblox game and a flashback.
Pikachu vs. Pancham Edit
In "Pikachu vs. Pancham", Gary finds Ash and suggests that they continue the battle. During the battle, Pikachu and Pancham are actually fighting to the death because they hated each other so much.
Face the Music Edit
In "Face the Music", he tells Ash about the Roria League before leaving.
Talent Breakout! Edit
In "Talent Breakout!" Gary goes to the play at Tom's school.
The Brunch Bunch Edit
In "The Brunch Bunch", Gary goes to Brunch with Ash and co.
Farewell, Young Trainers Edit
In "Farewell, Young Trainers", He picks up Ash and co. from Franklin.
Uncle Funtime 4 Edit
Gary only appears in 3 episodes of this series, but only 1 of them is a physical appearance. The other 2 are just cameos.
Lost in Natick Edit
In "Lost in Natick", he appears on a wall inside of an arcade.
Team Rocket's Mentorship Program Edit
He appears in a flashback of "Team Rocket's Mentorship Program".
The Train of Strength Edit
In "The Train of Strength", he says goodbye to Ash and co. as they head to New York City.
Season 28 Edit
CC2: Anime Extravaganza Edit
Ash and co. greet Dawn as she returns to Pallet Town to attend a Thanksgiving dinner planned by Ash's Mom. However, those plans change as Dawn finding a picture of Ash and Alex. The gang decides to go back to Franklin to see Alex. When they got to Franklin, Tom and the gang introduces themselves to Dawn. After spending a whole week together, they end up going to Thanksgiving dinner with the Connellys. After Thanksgiving, Ash and his friends decide to spend all of December in Franklin with the Connellys so they can go to Cape Cod during Winter Break. During the whole series, Ash and co. go on many crazy adventures while meeting Team 7 and the Straw Hats and celebrating the Holidays before parting ways.
School Daze 4: Road to the Omniverse Edit
Gary had his memory erased by Eon and was sent to an alternate timeline based on the original Pokemon games. However, he got his memory back after Ash reminded him of how he defeated Gary's Blastoise in the Johto League. Afterwards, he helped the gang rescue Misty and Brock and take down Eon before parting ways.
Gary has auburn hair and blue eyes. In the original series, Gary wore a long-sleeved purple shirt, a black necklace with a gold bead, dark blue pants and brown boots. In the Advanced Generation series and Diamond and Pearl series, he wears a black collared shirt, purple cargo pants, a black necklace with a lavender bead instead of the original gold one, purple wristbands, a light gray fanny pack, and black sneakers with a dark purple backpack. His Brunch outfit consists of a white short-sleeved dress shirt underneath a teal vest, a red tie, khaki trousers, and black dress shoes.
- In Gary's first appearance in Battle Frontier, Gary's new clothes resembled trainer Blue's clothes in Pokémon FireRed and LeafGreen.
- Gary is the counterpart of Blue in the Japanese Edition of the manga, Pokémon Special. Though, due to the fact that Pokémon Red and Green was not released in America, his name was changed to Blue in the manga and games for the English release.
- Gary owns many of the same Pokemon as his game counterpart: Blastoise (if Charmander is chosen and in most media), Alakazam, Arcanine, Fearow (Yellow only), Eevee (Yellow only), and befriended an Aerodactyl, another Pokemon that Blue owns, and owns an Electivire and Scizor, the evolved forms of Electabuzz and Scyther, Pokemon used by Blue in Pokemon Stadium and Pokemon Stadium 2.
- He also owns three of the same Pokemon as his manga counterpart: Scizor, Arcanine, and Alakazam.
- Gary's Electivire is his only Pokémon which is from a region other than Kanto or Johto (Electivire is technically from the Sinnoh region).
- Unlike Blue, Gary is shown to care about his Pokémon. Also, he is shown at least once kissing a Poké Ball before sending his Pokémon out. In the episode that this happened, The Battle of the Badge, Gary showed nervousness when Mewtwo used its psychic powers on Arcanine and Nidoking.
- Gary shares the same birthday as Trent Boyett: October 18th.
- Gary is the only anime guest star who doesn't switch to his old outfit.