Misunderstood and boasting a dark reputation, Thestrals are in fact among the gentlest creatures one can come across in the Forbidden Forest.

Harry on a Thestral flying over London from The Order of the Phoenix
Harry Potter and the Order of the Phoenix

Extracted from Harry Potter: The Creature Vault

In the first four Harry Potter films, the carriages that shuttle between Hogsmeade Station and Hogwarts castle appear to be pulled by nothing, but in fact they are pulled by Thestrals, which did not need to be realised visually until Harry Potter and the Order of the Phoenix. It is only after the events of Harry Potter and the Goblet of Fire that Harry is able to see these black, skeletal, dragon-faced creatures, as Thestrals are visible only to those who have seen death.

A concept illustration of a Thestral, from Harry Potter and the Order of the Phoenix.
Harry Potter and the Order of the Phoenix

Thestrals help transport Harry and other members of Dumbledore’s Army to the Ministry of Magic during Order of the Phoenix. A Thestral is also used as part of the plan to rescue Harry Potter from Privet Drive in Harry Potter and the Deathly Hallows – Part 1, ridden by Bill Weasley and his bride, Fleur Delacour.

The Thestral, a creature unique to the world of Harry Potter, is depicted as having a delicate walk, a quiet cry similar to whale song, and translucent, bat-like wings that enhance its mysterious, disturbing character. The Thestrals are computer- generated, but the creature shop created a full-scale model to ensure that its thirty-foot wingspan would fit into the Forbidden Forest set in Harry Potter and the Order of the Phoenix.

This model was cyber scanned for the digital artists to utilise. As the Thestral is so emaciated, the computer animators created a detailed skeleton, with special care taken to ensure that the creature’s thin skin didn’t get ‘sucked’ into its bones. The black colouring of the creature provided a challenge to the designers – a dark, gloomy black would not film well for the screen. It was determined that the model should be painted paler than assumed, and had a mottled colour scheme, giving the Thestral a moody radiance among the shadows of the forest set.

Harry and Luna look at Thestrals in the forest in a still from the Order of the Phoenix.
Harry Potter and the Order of the Phoenix

At times, the Thestral’s horselike anatomy worked against what was required in the script, specifically when Luna feeds the Thestral foal in the forest. Its long legs and short neck made it difficult for its head to reach the ground. The task was finally accomplished when the digital artists had the Thestral position its legs like a giraffe’s in order to scoop up the treat.

Adjustments also needed to be implemented for Thestrals in flight. The creatures only carried one passenger each in Order of the Phoenix, but to accommodate two passengers in Deathly Hallows – Part 1, the Thestral’s spine was elongated. The flight scenes were a composite of aerial cinematography and actors filmed riding a fully realised midsection of a Thestral in front of a blue screen. These sculpts had a jointed back and articulated movements that the actors could respond to. Placed on a pre-programmed motion-controlled gimbal, the Thestral model flew in unison with the filmed sequence.

Harry with Luna in the Forest looking at Thestrals.
Harry Potter and the Order of the Phoenix

Harry Potter: The Creature Vault book cover

Extracted from
'Harry Potter: The Creature Vault'