Isidore of Seville [7th century CE] (Etymologies, Book 12, 3:4): Shrew [sorex] is a Latin word, and it is so called because it gnaws and cuts things off like a saw [serra]. The ancients said saurex for sorex just as they said claudus for clodus [“lame”].The shrew-mouse [mus araneus, "mouse spider"] is called a spider because of its bite. - [Barney, Lewis, et. al. translation]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Quadrupeds 4.75): Mygale is an animal forbidden by [Jewish] law. Although it may sometimes be supported by strength in youth, yet from day to day and from year to year the more it grows old, the more it becomes pitiable. Finally, constrained by its wretchedness and weakness, it imagines itself to be meek, although by nature it is cruel. For when any one comes near it, it suddenly spreads poison. For it is a poisonous animal and fraudulently hostile to beasts. As the Experimentator says, it vexes horses and mules the most, and especially the pregnant mares; and in a strange way, when it has no power to press, it flatters itself with immoderate praise, to which, if power is ever given to it, it immediately reveals the cruelty hidden in its heart. This animal signifies the hypocrites and the malicious, of which their weakness, as a wise man says, lies no less daring, when their strength may be present. Brother Hugh of the Order of Preachers places this in the gloss on Leviticus. - [Badke translation/paraphrase]