Carter showed up in "Bulbasaur.the Ambassador!" as a one-off character. He runs a milk delivery operation and first meets Ash's group when they help him chase down some runaway milk cans that were rolling downhill. Grateful for the assist, Carter offers them a ride in his blimp to Ecruteak City, which they're all heading to anyway. The blimp drops them off near Moomoo Ranch before Ash and the others head out again.
Content compiled by AnimeList.moe from publicly available sources.
