Muttley was Dick Dastardly's dog. Dastardly & Muttley appeared in Hanna-Barbera cartoons Wacky Races and 'Dastardly & Muttley in their Flying Machines' (aka 'Stop The Pigeon').
Muttley, voiced by Don Messick, had three catchprases, all rather difficult to render in print. The first was his laugh, a kind of wheezing chuckle. The second was his muttered string of curses, uttered when Dick Dastardly had, as usual, delegated Muttley the dirty work. This sounded something like "Rasmdsmfsmdsm". Lastly, he could say "Yehyehyehyeh", in enthusiastic agreement. Other than this, he was pretty much mute.
Muttley had the peculiar ability to fly, like a helicopter, by spinning his tail around over his head. This was handy for when the aforementioned Flying Machines inevitably became Falling Machines.
When Dick Dastardly really needed Muttley's help, he could persuade Muttley to do his bidding by offering him a medal. Upon receipt of the medal, Muttley would be absolutely ecstatic, to the point where he would float up into the air, and then gently float to ground, like a feather. This little routine was lifted almost exactly from the dog Snuffles on the Quick Draw McGraw show, who behaved like this on receipt of a doggie treat.
Later, Hanna-Barbera created a dog detective character named Mumbly, a kind of cross between Columbo and Muttley, who looked just like Muttley but with a trenchcoat.
The Muttley files! - http://www.hotink.com/wacky/mfiles/