Wonderful (ワンダフル Wandafuru) is the deuteragonist in the special episode, Battle! Cat-Model Robots VS Dog-Model Robots.
Wonderful was sent to Nobita in order to replace Doraemon and helped Nobita study while trying to keep Doraemon away from him. Using a soundproof ball to keep Doraemon away. While trying to find Doraemon, his eyes looked very devilish, However, he was told by Nobita that he wanted to see his room. Nobita was later taken by Sewashi, tricking Wonderful. After being tricked, he took a look at Nobita's diary. Looking at his diary, Wonderful learned the true meaning of friendship.
Wonderful is a dog-shaped robot unlike Doraemon, he stands on two feet, he wears a red collar around his neck, his neutral eye colour is yellow, however, when Nobita disobeys his orders, they will turn to red.
Wonderful is shown to be very intelligent and kind, helping Nobita with his homework. However, he had a deep hatred for Doraemon and did everything in his power to replace him. Also, while Doraemon is short-tempered, loudmouthed, prideful and too lazy to help Nobita with his homework, Wonderful is levelheaded, soft-spoken, modest, and very helpful with Nobita in his studies.