Extracted from Harry Potter the Creature Vault.
The films of the Harry Potter series showcased a large amount of creatures, none so large as the giants. Giants can reach up to twenty feet in height, only four feet taller than trolls, and only as proportionately higher in intelligence. Prior to the events of Harry Potter and the Order of the Phoenix, as Voldemort is gathering his strength and his supporters, Hagrid is sent to parlay with the giants. During this journey, he finds his giant half brother, Grawp.
The giants who participate in the battle of Hogwarts in Harry Potter and the Deathly Hallows – Part 2 were to be computer-generated, but the digital crew knew it would be beneficial to start the design process with film of live-action actors. Prosthetics were created to scale up features on the actors’ faces. Actors of varying oversized proportions wore the prosthetic makeup, along with loincloths, and were filmed running on treadmills. Then these green-screened movements were imported into a digital format. The giants’ faces were scaled up again and distorted to lessen their human features. The bottom half of the giants’ legs was made broader to suggest a lower center of gravity, and some were given feet with elephant-like toes. The giants’ costume design included belts of skulls and human teeth, and hairstyles that contained branches and leaves.
In Harry Potter and the Order of Phoenix, half-giant Hagrid brings Harry Potter, Hermione Granger, and Ron Weasley to meet his half brother, Grawp, who he has hidden in the Forbidden Forest. Grawp is sixteen feet tall in the films. Although fully computer-generated, the creature effects shop constructed Grawp’s head at full scale in an economical move to explore the finer details of his skin and hair, which always present challenges in CGI. Additionally, Grawp’s head was used on the Forbidden Forest set in Harry Potter and the Order of the Phoenix for the actors’ benefit as a sight line and as reference for the cinematography and lighting crews.
A puppeteer dressed in a blue-screen suit was raised via a hydraulically controlled rig to the height of sixteen feet to enact the character. Grawp’s arms were also constructed practically and operated by the puppeteer, important in gauging how far they would reach in order to block the scene. And Grawp’s right hand was created to use in front of a green screen. Emma Watson (Hermione Granger) and Imelda Staunton (Dolores Umbridge) were filmed riding a motion-controlled giant’s hand as part of being picked up by Grawp, then the hand was replaced by its digital version and the two elements were painstakingly composited together.