From LOCUS SOLUS by Raymond Roussel:
…In the year 831, Alexander brought back a magnificent giant bird from his victorious campaign to Babylonia.
The animal was housed in Alexander's bedroom, where it was tethered by a golden cord, not far from the royal bedchamber.
Apathetic and cold, the bird showed no affection for the king, who kept it solely for its radiant beauty.
Among the captives was a Persian named Bruces, whom Alexander had allowed into his inner circle. Although he feigned affection, he harbored a deep hatred for Alexander. Bruces intended to bribe one of Alexander's servants to assassinate and halt the conqueror's triumphal march. He chose Guzil.
Guzil agreed to the deal and sought a way to win the prize without exposing himself. He had noticed that the bird was very teachable and remarkably gifted in all kinds of training. He devised a plan to train the bird to kill Alexander without anyone being blamed for his death. Each time, he lay on the king's bed and trained the bird to make a large noose with the golden cord using its beak and to place it around the king's neck.
Then he mimicked the movements of a sleeper, teaching it to use every opportunity to gradually pull the dangerous cord down to the back of the king's neck and to tug on the rope with the full force of its enormous wings.
During the king's first slumber, the bird placed the noose around its master's neck.
But when Alexander writhed in his death throes, the athlete Vyrlas rushed into the room, overpowered the bird, and loosened the fatal knot.
The investigation led to Gozil's arrest.
Guzil was killed, as was the dangerous bird, which would have been capable of carrying out further criminal attacks on any sleeper agent in the future.