Legolas shoots down the Winged Steed of a Nazgul

Stroke by stroke they laboured on. In the darkness it was hard to be sure that they were indeed moving at all; but slowly the swirl of the water grew less, and the shadow of the eastern bank faded back into the night. At last, as far as they could judge, they had reached the middle of the stream again and had driven their boats back some distance above the jutting rocks. Then half turning they thrust them with all their strength towards the western shore. Under the shadow of bushes leaning out over the water they halted and drew breath.

Legolas laid down his paddle and took up the bow that he had brought from Lórien. Then he sprang ashore and climbed a few paces up the bank. Stringing the bow and fitting an arrow he turned, peering back over the River into the darkness. Across the water there were shrill cries, but nothing could be seen.

Frodo looked up at the Elf standing tall above him, as he gazed into the night, seeking a mark to shoot at. His head was dark, crowned with sharp white stars that glittered in the black pools of the sky behind. But now rising and sailing up from the South the great clouds advanced, sending out dark outriders into the starry fields. A sudden dread fell on the Company.

‘Elbereth Gilthoniel!’ sighed Legolas as he looked up. Even as he did so, a dark shape, like a cloud and yet not a cloud, for it moved far more swiftly, came out of the blackness in the South, and sped towards the Company, blotting out all light as it approached. Soon it appeared as a great winged creature, blacker than the pits in the night. Fierce voices rose up to greet it from across the water. Frodo felt a sudden chill running through him and clutching at his heart; there was a deadly cold, like the memory of an old wound, in his shoulder. He crouched down, as if to hide.

Suddenly the great bow of Lórien sang. Shrill went the arrow from the elven-string. Frodo looked up. Almost above him the winged shape swerved. There was a harsh croaking scream, as it fell out of the air, vanishing down into the gloom of the eastern shore. The sky was clean again. There was a tumult of many voices far away, cursing and wailing in the darkness, and then silence. Neither shaft nor cry came again from the east that night.

The Fellowship of the Ring, Book Two, Chapter 9: The Great River.