Tad is a trainer who showed up in the episode "Charizard Chills." He's best known for being one of the stronger competitors in his area—he'd actually beaten Rudy, the Gym Leader of Trovita Island, and won his hometown's biggest Pokémon tournament.
Ash and the group first ran into him when Tad nearly mowed them down with his boat, which obviously got Misty fired up. After apologizing, Tad recognized Ash from Rudy's talk about him and challenged him to a two-on-two battle on the spot. His Poliwrath was genuinely strong, taking out both Pikachu and Charizard. Though to be fair, Charizard wasn't exactly cooperating with Ash at that point. Tad told Ash he'd be down for a rematch once he figured out how to actually train the thing.
The turning point came the next day. Team Rocket grabbed Pikachu, but Ash went all out to get him back, and in doing so finally earned Charizard's trust. Once Tad saw that Ash had his act together, he wanted that rematch. This time Charizard listened, and Ash won decisively—Charizard knocked Poliwrath down and finished it with Seismic Toss.
He appeared in a brief flashback years later in "The Fires of a Red-Hot Reunion!"
Content compiled by AnimeList.moe from publicly available sources.
