Most scientists believe that the Loch Ness Monster is not real, and they say that many of the seeings are either hoaxes or pictures of other mistaken existing animals. However, a popular theory among believers is that "Nessie" is a plesiosaur, an extinct meat-eating aquatic reptile that lived in the Mesozoic era. The Loch Ness monster has also been described as an elephant, eel, and other animals.