Mouse Master is a character that appeared in the episode "Karate Clumsy". He is an elderly mouse being whom the Smurfs have befriended when they landed in his village and entered into his house. He is a karate expert who tried to show Clumsy some steps in karate, only to find that his student was too inept to follow his instructions. He helped Clumsy and Smoogle rescue his fellow Smurfs and the village mice from being captives to the evil ninja rat who had used them to clean his castle. Mouse Master was also instrumental in helping the Smurfs find a cure to Papa Smurf's induced sleeping sickness caused by the bite of a slumber bug in the episode "Papa's Big Snooze".