Three detailed expositions of excellence from the Mesnagier De Paris:

Eel

[L]'anguille qui a menue teste, becque délié, cuir reluisant, ondoiant et estincelant, petis yeulx gros corps et blanc ventre, est la franche. L'autre est à grosse teste, sor ventre, et cuir gros et brun.

The eel which has a little head and a slim beak, shining, wavy, sparkling skin, small eyes, a large body with a white belly is the true eel. The other has a large head, a yellow belly, and thick brown skin.

Cheese

Non mie blanc comme Helaine,
Non mie plourant com Magdalaine,
Non Argus, mais du tout avugle,
Et aussi pesant comme un bugle:
Contre le poulce soit rebelle,
Et qu'il ait tigneuse cotelle.
Sans yeulx, sans plourer, non pas blanc,
Tigneulx, rebelle, bien pesant.

Not near so fair as Helen was,
Nor weeping like the Magdalene,
No Argus, but altogether blind,
And dense and heavy as an ox:
Against your thumb it should rebel,
And it must have a scabrous rind.
Without eyes or tears, and not white,
Scabrous, firm, and good and dense.

Horse

Be aware... that a horse should have sixteen characteristics. Three qualities of a fox: short, straight ears; good hair; and a strong tail full of hair. Four qualities of a hare: a lean head; extreme wariness; light movements; and speed. Four qualities of an ox: a wide, large, and broad chest; a large belly; large eyes that stand far out from the head; and low jointedness. Three qualities of an ass: good feet; a strong backbone; and gentleness. Four qualities of a maiden: a beautiful mane; a beautiful chest; beautiful loins; and large buttocks.

That last I could not find online; it is from Tania Bayard's translation.

I count eighteen characteristics of a horse. It's interesting to compare with Xenophon (the attribution to whom of On Cheeses and Eels is apparently apocryphal):

His neck should not hang downwards from the chest like a boar's, but stand straight up to the crest, like a cock's; but it should be flexible at the bend; and the head should be bony, with a small cheek. Thus the neck will protect the rider, and the eye see what lies before the feet. Besides, a horse of such a mould will have least power of running away, be he never so high-spirited, for horses do not arch the neck and head, but stretch them out when they try to run away.

Would someone please tell me I'm translating "tigneuse" wrong?