Sidney Sime (1865-1941).
Sidney Sime (who signed his works S.H. Sime) was an English artist, and this was an illustration for "Poltarnees, Beholder of Ocean" in Lord Dunsany's A Dreamer's Tales, published in 1910.
A Dreamer's Tales is the fourth book by Irish fantasy writer Lord Dunsany, considered a major influence on the work of J. R. R. Tolkien, H. P. Lovecraft, Ursula K. Le Guin, and others.
Sidney Sime’s artwork is amazing, thanks for sharing!