эриэн үөн

Etymology
There are various mottled snakes in Siberia that could have triggered this association. For a similar semantic development (of reusing animal names to refer to very different animals) see also the various English animals prefixed with sea (sea horse, sea cow, etc.).

As a side note, compare the "speckled band" in the Sherlock Holmes tale The Adventure of the Speckled Band (Arthur Conan Doyle, 1892).

Noun

 * 1)  snake