Shrike's Thorns

The Shrike's Thorns are the defining lethal features of the creature known as the Shrike, a guardian entity residing within the Time Tombs on Hyperion. The Shrike is described as a menacing half-mechanical, half-organic four-armed creature composed of razorwire, thorns, blades, and cutting edges, having fingers like scalpels and long, curved toe blades. It has the ability to control the flow of time, and may thus appear to travel infinitely fast.

The Shrike may kill victims in a flash or it may transport them to an eternity of impalement upon an enormous artificial 'Tree of Thorns,' or 'Tree of Pain' in Hyperion's distant future. The Tree of Thorns is described as an unimaginably large, metallic tree, alive with the agonized writhing of countless human victims of all ages and races. It is also hinted in the second book that the Tree of Thorns is actually a simulation generated by a mystical interface which connects to human brains via a strong and pulsing (as if it were alive) cord.

The name Shrike seems a reference to birds of the shrike family, a family of birds that impales their victims on thorns, spines, or twigs.