Whitney
Whitney (called Akane in the original Japanese) is Goldenrod City's Gym Leader and the expert on Normal-type Pokémon. She hands out the Plain Badge—a name that works as a pun, since Whitney herself runs a farm and specializes in Normal types. Her English name references white islands, playing on the "plain and colorless" theme; her Japanese name, Akane, likely refers to either the madder plant or a deep red color, possibly inspired by her hair. Her signature Pokémon is an especially formidable Miltank.
In the anime, Whitney is the niece of a Miltank farmer and has an oddly useful quirk: she always finds her way wherever she needs to go, but only when she has absolutely no idea how to get there. It's a talent that comes with a hefty dose of clumsiness. She accidentally leads Ash and his friends on a detour through Goldenrod City that ends up at the Goldenrod Galleria before Ash realizes she's actually the gym leader. Their first battle doesn't go well for him—his team handles her Nidorina and Clefairy fine, but her Miltank shuts down everything he throws at it. After Ash spends some time working at her uncle's farm and helps foil a Team Rocket plan, he gets a rematch. This time, Pikachu has the speed and tactics to outplay and defeat her Miltank.
In the Pokémon Adventures manga, Whitney's a completely different character: an actress and close friend of DJ Mary, to whom she gave a Smeargle. She ran into Gold at the Radio Tower and they clashed hard enough to end up challenging each other to a bike race. Suicune, notably, doesn't consider Whitney a particularly strong Gym Leader and refuses to acknowledge her as a potential partner—she's one of only two Johto leaders that Suicune dismisses (the other being Pryce). She uses a pair of Cleffa and Igglybuff that confuse and stun opponents before Miltank moves in for the kill. She ends up being the first to figure out that Pryce is actually the villain known as the Mask of Ice. At the Pokémon League, she faces Misty and loses to a Hyper Beam from her Starmie.
Content compiled by AnimeList.moe from publicly available sources.