One of the French classics is ‘Le Roman de Renart’. Despite the title, it is not a novel like those you can read today: Le Roman de Renart was written in verse, usually octosyllabic (eight-syllable verse) with rhymes.
Another feature, Le Roman de Renart has had more than 20 authors. One of the first known is Pierre de Saint-Cloud, who starts ca. 1170-1178, telling the adventures of a character called “Renard.” He is the first to do so in writing, but he did not invent these adventures, he merely put an oral tradition on vellum. In the thirteenth century, other authors continue these stories. Most of these authors are anonymous, as are the illustrators. There are thus many copies of this manuscript and it has been translated in different languages as well . One of the copies is in the Bibiliothèque nationale in Paris ; it is from the 14th century.
The tale is entirely based on animalistic figures, one of them being Tardif, the snail . It is shown in four miniatures as a stylised, right-coiled shell in top-view, with the head of the snail peeking out and adorned with two tentacles, and a humanised face (eye-spot and mouth).
Folio 16v has the first appearance of Tardif; the paint has partly been lost.
Folio 124r is only a partial miniature, where Tardif is seen on the left-hand side. The shell is drawn giving the impression of axial riblets.
On folio 125r, the snail head looks more like a hare (one of the figures that regularly re-occurs in the ‘knight v. snail’ theme).
Folio 143v has a miniature showing Tardif (still looking similar to a hare) with a shield opposing Renart, who sits on a horse with his sword raised.
Finally, folio 103v has a nice example of a maniculum , in this case a hand coming out of a stylised, left-coiled shell, the index finger pointing to a text row (for emphasis), and three other fingers fanning down. They bear resemblance to the four tentacles of a snail.
This inverted world where animals talk and act humanely is also an example of the topsy-turvy land used by Pinon  in his explanation (post #17).
 http://fr.wikipedia.org/wiki/Roman_de_Renart (20.i.2014).
 BNF, Ms. Français 12584, 157ff. http://gallica.bnf.fr/ark:/12148/btv1b60004625 (permalink).
 See e.g., http://bit.ly/1cY5sGn, for more examples (12.i.2014).
 Pinon, R. (1980). From illumination to folksong; the armed snail, a motif of topsy-turvy land. In: Newall, V.J. (ed.), Folklore studies in the twentieth century. Proceedings of the Centenary Conference of the Folklore Society: 76–113. Boydel & Brewer, Woolbridge / Rowman & Littlefield, Totowa.