Yagis

The Yagis is from the Kwakiutl people in Vancouver. It is a sea monster and has been described as a giant snake, an aquatic fire breathing horse, or a man-eating turtle. It flips boats by creating massive waves and then eats the sailors.

Citations:

Maberry, Jonathan. Vampire Universe: The Dark World of Supernatural Beings That Haunt Us, Hunt Us, and Hunger for Us. United States, Kensington Publishing Corporation, 2006.