He stops Layton and Luke from heading to the observation car of the train to find the girl holding a dog until they have solved 12 puzzles, and then his. When they do solve at least 12 puzzles, he applauds for their acomplisment.
Grousley is one of the many passengers on the Molentary Express. While he may not look the part, the eccentric Grousley is actually a very well-to-do artist and friend of Beluga's. He gets inspiration from the natural scenery visible on train rides.