Milton is Whitney's uncle and runs a Miltank dairy farm on the outskirts of Goldenrod City. He's best known for appearing in the episode "A Dairy Tale Ending," where he plays host to a rematch between Ash and his niece.
On the farm, Milton handles the day-to-day work of milking and caring for his Miltank while producing his own dairy products like cheese and yogurt. Whitney clearly has a lot of respect for the operation—she considers it the greatest dairy around.
Ash had already lost to Whitney in an official Gym battle, but he gets a second chance when Milton offers him an informal rematch on the farm. This time, Ash brings three Pokémon to the fight while Whitney sticks with just her signature Miltank. Ash manages to pull out a win, though he's unsure whether it counts as a legitimate victory. Milton reassures him, saying that what really matters in earning a Badge is defeating the Gym Leader's strongest Pokémon—which Ash did. Satisfied, Whitney hands over the Plain Badge.
The farm itself is inspired by the Moomoo Farm location from the games, though the show places it near Goldenrod City rather than on Route 39 like the original.
Content compiled by AnimeList.moe from publicly available sources.
