Pink elephant
Seeing pink elephants is a figure of speech, that is used to describe a hallucination which is caused by alcohol, or delirium tremens. Jack London was among the first to use the term, in 1913. In the autobiographical novel John Barleycorn, he describes one kind of alcoholic,  as "the man whom we all know, stupid, unimaginative, whose brain is bitten numbly by numb maggots; who walks generously with wide-spread, tentative legs, falls frequently in the gutter, and who sees, in the extremity of his ecstasy, blue mice and pink elephants. He is the type that gives rise to the jokes in the funny papers."  A reference to pink elephants occurs in the 1941 Disney animated film Dumbo. Dumbo, takes a drink of water from a bucket spiked with champagne and  begins to hallucinate singing and dancing elephants in a segment known as "Pink Elephants on Parade".