Shrunken head

In the Muggle world, A shrunken head is a human head that has been originally used for ritual or trade and served as decoration for some ethnic groups, while in the wizarding world, they have the ability to talk and served as a guide in travelling (in the Knight Bus for example) and guards in a house or inn (for example is in Madam Rosmerta's Three Broomsticks Inn.)

1993-1994

 * Harry Potter first encountered a shrunken head when travelling on the Knight Bus from Little Whinging to The Leaky Cauldron.
 * Ron Weasley and Hermione Granger were prevented from entering Three Broomsticks Inn by shrunken heads.

1995

 * When Harry Potter brought to 12 Grimmauld Place, Mrs. Weasley assisted him to Ron and Hermione's room upstairs. While they're passing in the dark staircase. Harry saw a row of shrunken heads mounted on plaques on the wall. In a closer look, he noticed that the heads belonged to house-elves.

1996

 * Hermione mentioned once that Vincent Crabbe had a shrunken head that has been confiscated by Argus Filch because any Dark objects are not allowed in the school.

Behind the scenes

 * Although the shrunken heads were additional characters for the film adaptation of Harry Potter and the Prisoner of Azkaban, and never appeared or mentioned even in the previous Harry Potter novels. J.K. Rowling liked the idea. She added it in her next novels, Harry Potter and the Order of the Phoenix and Harry Potter and the Half-Blood Prince describing as a dark object.

Appearances

 * Harry Potter and the Prisoner of Azkaban (film)
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Half-Blood Prince