§ Of Beren and Lúthien The Silmarillion

So great was the horror of his approach that Huan leaped aside. Then Sauron sprang upon Lúthien; and she swooned before the menace of the fell spirit in his eyes and the foul vapour of his breath. But even as he came, falling she cast a fold of her dark cloak before his eyes; and he stumbled, for a fleeting drowsiness came upon him. Then Huan sprang. There befell the battle of Huan and Wolf-Sauron, and howls and baying echoed in the hills, and the watchers on the walls of Ered Wethrin across the valley heard it afar and were dismayed.