"Seeing pink elephants" is a euphemism for hallucinations caused by delirium tremens or alcoholic hallucinosis, especially the former. The term dates back to at least the early 20th century, emerging from earlier idioms about seeing snakes and other creatures. An alcoholic character in Jack London's 1913 novel John Barleycorn makes reference to the hallucination of "blue mice and pink elephants" while describing the two different types of men that consume alcohol excessively. Another notable instance of the appearance of pink elephants in popular culture is the "Pink Elephants on Parade" section of the 1941 Walt Disney animated film Dumbo.