This is a interesting and cool Greek Mythology villain- Ketos the Sea Monster.
The Greek gods created Ketos/Cetus. This ferocious water monster had canine-like front legs, a long wide torso like that of a whale and a serpentine tail that was split at the end. It was amphibious and could survive on land or water. He is often depicted with pieces of him sticking up from the water rather than his entire body be showing. In some more recent depicting of the monster, he has whale-like attributes.