Most of the Nessie witnesses describe something with two humps, a tail, and a snakelike head. A V-shaped wash was also often mentioned, and such details as a "gaping red mouth" and horns or antennae on the top of the creature's head were sometimes noted. Nessie's movements have been studied, and the films and photos analyzed to determine what Nessie might be, if she exists.
There are numerous theories as to Nessie's identity, including a snake-like primitive whale known as a zeuglodon, a type of long-necked aquatic seal, giant eels, walruses, floating mats of plants, giant molluscs, otters, a "paraphysical" entity, mirages, and diving birds, but many lake monster researchers seem to favor the plesiosaur theory. Most scientists believe that these marine reptiles have been extinct for 60-70 million years, but others think it possible that after the last Ice Age the Loch may have been connected to the sea, and some of these dinosaurs may have been stranded. Others, like David Hall, feel that lake monsters could not possibly be plesiosaurs since plesiosaurs were cold-blooded reptiles that would have preferred warm oceanic currents to cold Scottish Lochs.
And we cannot afford to ignore the fact that sometimes Nessie is a hoax. Only one thing is certain about Nessie: that there are as many theories about her identity as there are theorists.