Mugger is an early version of Muttley appearing in Hey There It's Yogi Bear. Mugger is a mean spirited Dog who lives with his owners of the traveling Circus. He made Cindy Bear (Yogi's Girlfriend) look sike She is showing a High Wire act on a Telephone Wire. During this event, Mugger tried desprately to get Cindy twice. He tried to Bite and rip off Cindy's Blue Skirt and turn her half-naked so he can humiliate her.
Yogi and Boo Boo came to Cindy's rescue and Mugger was defeated when he was locked up in his own cage.
Mugger was appear in full-length-animated film of Yogi Bear along with his owners Grifter and Snively on the circus truck on the roadway in the night when Mugger out the truck he sniffs something when Cindy Bear wakes up she hears the noise something when Mugger barks and scared Cindy away and he chases her to the telephone wire Mugger shows Grifter and Snively got a trained Cindy to the high-wire bear. after Yogi and Boo Boo are left Jellystone on the train that night at the circus Grifter tells everyone in town to welcome the new star act the one and only Cindy the high-wire walking bear and Snively tells Mugger to get ready Snively tells Cindy to come out and Mugger barks and scares her Cindy up the top the pole. after Yogi came Cindy back to rescue her Grifter, Snively and Mugger are really good acting finding Cindy off the train and got some money Snively tells Grifter to needs another bear just then Yogi Bear arrives in the tent to tells Grifter, Snively and Mugger to take Cindy back to Jellystone Park when Grifter show him away Snively and Mugger follows them and Yogi sees her when Grifter kicks Yogi in the cage with Cindy and locked him out Grifter tells Snively to guard this key and Grifter tells Mugger to guard Yogi and Cindy in the cage and Mugger barks at them. that night they went to sleep at the circus but not Yogi's pal Boo Boo got this key out off Snively's hat and rescues his friends and Yogi locked Mugger in the cage and they are escaped.