This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Mugwump (Canadian folklore)
The Mugwump is a lake monster which has been alleged to live in Lake Timiskaming, on the border of the Canadian provinces of Ontario and Quebec. In 1995, a witness recalled the Mugwump as having a round head and nose like an animal. Two ice fishers alleged to have seen a black, glistening head through their fishing hole in 1982; they noted that it had protruding eyes, one of which was trained on them.
Another ice fisherman reported that he'd seen the creature completely out of the water one winter night, that it had a head similar to that of a dinosaur, and that it was long enough to curl around a number of fishing huts at once. A married couple which claimed to have witnessed the Mugwump swimming in 1978 reported that it had a humped back and no fins.