Gelett Burgess' "The Purple Cow"

Today’s poem is one of the most-anthologized works of light verse in the English language–and just plain fun.

Frank Gelett Burgess was an American artist, art critic, poet, author and humorist. An important figure in the San Francisco Bay Area literary renaissance of the 1890s, particularly through his iconoclastic little magazine, The Lark, and association with The Crowd literary group. He is best known as a writer of nonsense verse and for introducing French modern art to the United States in an essay titled "The Wild Men of Paris." Burgess coined the term "blurb."

-bio via Wikipedia