David Jr. appears in The Legend of Zelda: The Wind Waker, and Minish Cap. He helps Tingle and dresses up like him and his bothers, Ankle and Knuckle, but is not actually related to any of them.
Tips: Build from the head down. The arms and legs can be tricky, so when you get to them build from the hands or feet upwards, and complete the whole limb before attaching it to the body and carrying on. You will probably need to use weights to help it stand up, and seal it at his bottom.