¿Und?

As near as I can make it out.

Jam Arsa Mentvla Frigesco
Now I am chilled by a burning/flaming membrum virile.
But JAMF is also a well-known acronym, q.v.

Ergo merda stercissima atque micturio hominium sum.

Which, as I wrote earlier, should be:

Ergo merda stercorissima atque micturio hominium sum.
Therefore I am the filthiest dung and the urine of men.

Seems to be a play on Man is the measure of all things.

Hyokheutes Mesembrinos. 1369. Homunculus humilis atque anserculus.

This one took me a while, but it seems to be:

Greek huos 'pig, hog' + ?? okheutes 'lewd person, lecher'. And mesembrinos 'belonging to noontide; southern'. Lowly, little man and the gosling.

I was hoping Varaha would give us his translation, but he seems a tad shy.

Ceci n'est pas un seing.