What's the meaning of a knight fighting a snail in medieval book illustrations?

Replying to the meaning of the top answer for: Breviary of Renaud and Marguerite de Bar, British Library, Yates Thompson MS 8, f. 294r In this particular depiction, an interpretation I've heard, but did not read, that I particularly like: The animals are actually representing traits of things it would elsewise depict. On the left you have a dog riding a rabbit. The dogs' expression is warlike and aggressive, this might reflect the knight it is supposed to be depicting. You might even be able to know which knight in particular it is based on the coat of arms the dog carries. The rabbit, known for cowardice is looking up at its rider afraid. I'd say we have a knight riding a horse on the left. On the right, we see a rabbit riding a snail. Once again, an anxious expression is on the rabbit. It's a coward. The coat of arms might even let us know a particular knight that is cowardly. The snail has the face of an old man... this seems to me that the horse is old and slow, slow as a snail. Ultimately, I think the picture depicts a knight charging another knight and it is probably the knight on the left that wins. I think this may be common, depicting people as animals that represent certain traits? We see this in Japan as well with the Choju-Jinbutsu-Giga scrolls. That's just a fun interpretation that I like and think sticks well.

Beverley Nank, who is a curator at the British Museum, says that snails in manuscripts were drawn to symbolize cowardice. She even analyzed the manuscript images posted above.

Nenk said, 'snails were often depicted in the margins of medieval illuminated manuscripts, thought to symbolise cowardice. That could mean it is “a satirical reference to cowardly or non-chivalric behaviour of opponents in battle, or as a parody of the upper or knightly classes”.'

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"In it are several depictions of snails, including one of a knight in a snail shell on folio 1v, suggested to be a symbol of cowardice. No close parallel to this mount has been identified, but the general style and subject matter suggest a 13th to early 14th century date."

Source

"The knightly exploits of Sir Joffroy are counterbalanced on fol. 1v (fig. 6) by a chivalrous figure mounted on a dog and curled up in a snail’s shell, the symbol of cowardice."

Source

There is actually an entire scholarly article written about snails in manuscripts which says,"...the principal connotation of the motif appears to be the derision, or the exemplification, of human cowardice."

Source : Medieval Academy of America, The Snail in Gothic Marginal Warfare, Lilian M. C. Randall. Speculum,Vol. 37, No. 3 (Jul., 1962), pp. 358-367 :

This is an example of decorative marginalia, which is quite common on medieval manuscripts. Sometimes the marginalia relates to the context of the subject of that page of the manuscript, but often it appears to have been quite random.

One fairly well-known group that I'm personally particularly fond of is the so-called animals at war which includes images like this:

• Breviary of Renaud and Marguerite de Bar, British Library, Yates Thompson MS 8, f. 294r

Another famous example is the nun picking penises from a phallus tree in the Roman de la Rose manuscript owned by the Bibliothèque Nationale de France in Paris (MS. Fr. 25526, f. 106v). (Available to view as a digitised document on the Bibliothèque Nationale de France's BNF Gallica website)

The Snail Combat Motif

In general, the meanings that should be attributed to the images that appear in marginalia is unclear, and you will find volumes of speculation on the subject. However, for the specific group you are interested in, the paper The Snail in Gothic Marginal Warfare by Lilian Randall may be helpful.

This motif emerged in Northern France in the late 13th century, and spread from there to English and Flemish marginalia. Lilian Randall's paper suggests a range of possibilities for interpreting the designs.

These interpretations range from the idea of simply fighting the snail as a pest (considering the damage that snails could do to vineyards), to linking the snail with a nickname given to the Lombards (who were frequently disparaged in the early Middle Ages).

She even notes a possible connection a modern version of the Mother Goose rhyme:

"Four-and-twenty tailors went out to kill a snail".

It is clear that Lilian Randall's own preference is for the link with the Lombards. She states:

From the assembled evidence the three questions regarding the origin of the marginal illustration can now be answered as follows: the predilection for the literary snail combat theme can be explained by the manifest current anti-Lombard sentiment; the rapid diffusion of the motif reflects the international character of the Lombards' professional activities; and finally, the concentration of the motif in late thirteenth- and early fourteenth- century manuscripts mirrors the intense reaction to a current development which gradually lost its appeal along with its novelty.

However, it is important to note that she she also concedes that the images could have had multiple meanings in different times and places.