There are more than thirty different species of hare from around the world, but there can be little doubt that Tolkien had in mind the European hare (also called the brown hare), the kind that is by far the most commonly found in the British Isles.

'Hare' is an old word, with similar cognates in many languages. Its origins are uncertain, but it has been speculated that it may ultimately derive from a root-word *khas- meaning 'grey'.