You know what would be cool? A money Pokemon. But not live or possessed money, that would feel unnatural, but something like a Dark-type anaconda that has a Pokedollar on its tail and tricks people into grabbing the tail, only to be swallowed whole by the snake. Like a money on the fishing line prank, but more aggressive.
That or a piggy bank that evolves into a boar with a steel mouth like a safe box.