The Wind-Up Toy is an item in Nintendogs that falls under the category of Toys in the Supplies. It is a wind-up grey robot with pink shoes that walks towards dogs. It can be found at the Discount Store if you have enough Trainer Points (unlocked at 10,000). It sells for $24 at the Secondhand Shop.
DS: "This retro toy is highly collectible and valuable among toy collectors."