You're a trainer in the Johto region, looking to challenge the Elite Four and become the champion. You've just finished obliterating Bugsy's team with your Cyndaquil, but as you reach the gates to Goldenrod city, you groan as you realize you'll have to face HER. Whitney. The only gym leader to also be a pokémon, an anthropromorphic miltank. You walk into the gym and find it to smell vaguely unpleasant, like a cow. Whitney approaches you, and she looks exactly as you pictured her. A humanish figure, with human hair and some human features here and there, but most of it is pure unadulterated dairy miltank. She has both human boobs and a set of miltank udders. It is strangely adorable.

"Hi! I'm Whitney! Everyone was saying a Pokémon couldn't be a gym leader, so I proved them all wrong! Us pokémon are super-cute, don't ya think? Oh, you want to battle? I'm warning you- I'm good, miltank mil!"