This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Ogopogo (Canadian)
In Canadian folklore, the Ogopogo is a lake monster said to inhabit Okanagan Lake in British Columbia, Canada. Some scholars have charted the entity's development from First Nations folklore and widespread water monster folklore motifs. The Ogopogo now plays a role in the commercial symbolism and media representation of the region.
The lake monster has been mostly described as being a serpentine creature with smooth dark skin with a large body thicker than a telephone pole and being up to 50 ft in length. The monster has said to move at incredible speeds coiling its body in vertical undulations and propelling itself with a powerful tail.