Peter Pettigrew's silver hand

A silver hand was presented to Peter Pettigrew by Lord Voldemort in the summer of 1995, to replace his lost right hand. It appeared to be composed of metal and exhibited strength superior to that of its owner's former hand, capable of crushing a twig to fine dust. It was impervious to the Revulsion Jinx, and possibly any other spells. At first, it seemed to yield to Pettigrew's command, but Voldemort designed it to strangle its owner if any sign of treason or weakness was demonstrated. It was a sadistic and fail-safe way to ensure Pettigrew's punishment for a second attempt at desertion.

Creation
The potion which allowed Lord Voldemort to return needed three important ingredients: bone of a father, flesh of a servant and blood of an enemy. Pettigrew chopped his right hand off in order to supply the second ingredient.

When Voldemort returned, Pettigrew begged for a new hand, as Voldemort had promised him beforehand. Although Voldemort allowed Pettigrew to suffer the pain at first for thirteen years of disloyalty, Pettigrew's request was honoured and he was eventually presented with a robust silver hand that he could apparently control as though it was his real hand. Pettigrew tested it out by crushing a twig to fine dust, and was enormously grateful.

As Pettigrew lived the remainder of his life as a Death Eater, he adopted a habit of caressing his silver hand, such as when Severus Snape revealed him to be eavesdropping at Narcissa Malfoy and Bellatrix Lestrange's arrival to Spinner's End.

Betrayal and Execution
During their search for Lord Voldemort's horcruxes, Harry Potter, Hermione Granger, and Ron Weasley were captured and imprisoned at Malfoy Manor, Death Eater headquarters at the time. Following a disturbance from Dobby the house-elf, Disapparating with other prisoners, Pettigrew was ordered to investigate. As he went down the stairs, Harry and Ron tackled him and took his wand. Pettigrew made an attempt to strangle Harry using the silver hand. However, Harry reminded Pettigrew of saving his life four years ago, and Pettigrew released Harry in an unintended and momentary show of mercy. After Pettigrew tried unsuccessfully to undo that moment of weakness, the hand recognised Pettigrew as unfaithful to the Dark Lord and began strangling him. Despite Harry and Ron's attempts to intervene, the hand proved to be too powerful to succumb to their efforts and they were forced to watch helplessly as Pettigrew suffocated and died.

Behind the Scenes
In Harry Potter and the Deathly Hallows Part 1, Pettigrew is stunned by Dobby, instead of being strangled by his silver hand. Due to the fact that he doesn't appear in Part 2, his fate is unknown (though it's possible that Voldemort ordered the hand to strangle Pettigrew offscreen as punishment for allowing Harry and Ron to escape).

Appearances

 * Harry Potter and the Goblet of Fire
 * Harry Potter and the Goblet of Fire (film)
 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film)
 * Harry Potter and the Deathly Hallows
 * Harry Potter and the Deathly Hallows: Part 1
 * Harry Potter and the Deathly Hallows: Part 2