According to an article in The Herald Scotland, some students in U.S. religious schools are being taught that the Loch Ness monster is real and is a dinosaur.
The textbook Biology 1099, part of the Accelerated Christian Education (ACE) program employed by some fundamentalist religious schools, offers students this tidbit:
Are dinosaurs alive today? Scientists are becoming more convinced of their existence. Have you heard of the "Loch Ness Monster" in Scotland? "Nessie" for short has been recorded on sonar from a small submarine, described by eyewitnesses, and photographed by others. Nessie appears to be a plesiosaur.
In fact, while I'd personally like to believe in Nessie, all serious attempts to locate the legendary creature have failed to produce credible evidence, and in any case it's hard to see how a solitary dinosaur (or any other sort of lake monster) could survive on its own for many decades.
Why would a textbook make such a claim to start with? Because it's promoting a particular religious ideology that requires the Earth to be only a few thousand years old, and a living dinosaur would help to promote that idea. There's more on this in the article, which notes that in some states tuition in fundamentalist schools is partly supported by taxes.