
"The Unicorn in the Garden", The New Yorker (31 October 1939); Fables for Our Time & Famous Poems Illustrated (1940). This is a fable where a man sees a Unicorn in his garden, and his wife reports the matter to have him taken away, to the "booby-hatch". Online text with illustration by Thurber http://english.glendale.cc.ca.us/unicorn1.html
From Fables for Our Time and Further Fables for Our Time