Grocott & Ward, comps. Grocott’s Familiar Quotations, 6th ed. 189-?.

Snake

A needless Alexandrine ends the song,
That like a wounded snake drags its slow length along.
Pope.—On Criticism, Line 356.

We have scotch’d the snake, but not kill’d it.
Shakespeare.—Macbeth, Act III. Scene 2. (Macbeth to his Lady.)