After coming across his gym, Ash decided to battle A.J., who has never lost a battle, despite the gym not being official. During Ash's first try in the gym, A.J. comes out victorious. Team Rocket appears and takes A.J.'s Sandshrew, mistaking it for Ash's Pikachu. A.J. later got his Sandshrew back. After the defeat of Ash and Team Rocket, A.J. has past his previous number of ninety-eight victories and hit one hundred. With one hundred victories under his belt, A.J. and his Sandshrew travel the Kanto region to challenge the Gyms.
In the games
In Pokémon Yellow, A.J. appears as a Youngster on Route 9. The only Pokémon he uses is a Lavel 24 Sandshrew that knows the moves: Scratch, Slash, Sand Attack, and Fissure. After Red defeats him he states "I'll restart my 100-win streak with Sandshrew!".
Sandshrew is A.J.'s first Pokémon. Through strict training, A.J.'s Sandshrew has become powerful enough to defeat 100 opponents. After doing so, A.J. left to take on Kanto gyms.