If that is a living creature what does it eat to survive?
It seems that something that massive would clear all the fish out of a lake in no time at all.
Moss. Nessie eats moss, not fish. It’s a vegetarian, and eats moss and phytoplankton. If you look carefully at the wake, you’ll see a slight sheen; that’s the hydrocarbon waste product. Now & then, it also lets a methane burst go.