IO9's Cyriaque Lamar has dug through the Tulane University Louisiana Research Collection of Mardi Gras costume and float designs and uncovered an utterly bizarre float entered in 1873 by the Mistick Krewe of Comus, who set out to lampoon both Charles Darwin and the Reconstruction. They dressed up as their idea of the "missing link" with heavy racist overtones. They didn't make it through the parade -- the police shut them down at Canal Street.
In 1873, Mardi Gras revelers from the Mistick Krewe of Comus — unversed in this newfangled evolutionary theory and angry at the Northern interlopers — dressed up as the "missing links" between animals, plants, and humans. Therefore, you had frightening human-grape and human-corn hybrids running around and fauna baring the faces of Ulysses S. Grant, other hated politicians, and Darwin himself.
You can see these costumes here, but this being 1870s Louisiana, the masquerade was absurdly racist.
Lamar's post details other floats and costumes, including an 1884 version of the Aeneid, an 1888 Middle Ages mythos float, an 1892 tribute to fruits and vegetables, an 1895 Asgard, a 1900 Alice in Wonderland, and a 1925 Japanese mythology set.