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 were 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.
He have a appearance that looks like a dog, he only stands two feet instead of four, he wears a red collar around his neck, his eye colour were yellow, however, when Nobita disobey his order, it will turned to red.
Wonderful is shown to be very intelligent and kind, helping Nobita in 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.