Adam Clarke on Leviticus 11:29

The weasel - חלד choled, from chalad, Syr., to creep in. Bochart conjectures, with great propriety, that the mole, not the weasel, is intended by the Hebrew word: its property of digging into the earth, and creeping or burrowing under the surface, is well known.

The mouse - עחבר achbar. Probably the large field rat, or what is called by the Germans the hamster, though every species of the mus genus may be here prohibited.

The tortoise - צב tsab. Most critics allow that the tortoise is not intended here, but rather the crocodile, the frog, or the toad. The frog is most probably the animal meant, and all other creatures of its kind.