This year marks the 15th anniversary of the release of Harry Potter and the Philosopher's Stone and to celebrate, Warner Bros. Studio Tour London The Making of Harry Potter is running a series of special features, offering visitors the opportunity to go behind the scenes and discover how the franchise was born on screen. The first of these special features will be a look at Harry Potter's favourite half-giant, Hagrid! Between March 25th and April 17th 2016, visitors to the Warner Bros. Studio Tour London The Making Of Harry Potter will find out how film-makers turned 61 Robbie Coltrane into the lovable Keeper of Keys and Grounds of Hogwarts. Fans will also get a chance to see two costumes which were created specifically for Hagrid, one which was worn by Coltrane and the other which was made 25% larger and used by his 610 body double, England rugby star Martin Bayfield. Hagrid's larger-than-life sized animatronic head is just one of the props Sarita Allison, a Creature Effects Artist, has been giving a spring clean. Sarita began her career as a hair and makeup artist and went on to join the 140-strong group of special effects artists working on the Harry Potterfilm series, that were involved in creating and applying Goblin masks. From re-curling each eyebrow hair to repainting every wrinkle, Sarita has been busy giving each individual mask the makeover treatment. Rebeus Hagrid's animatronic head has received particular special attention with his famous bushy beard being perfectly primed. https://www.youtube.com/watch?v=YFSWfGaKoac&feature=youtu.be It takes a lot of work to create each Goblin head. Each hair making up the eyebrows and hair line was required to be punched and inserted one at a time. An individual Goblin head took between two - four days to be paint and could take up to six days to complete. It's this kind of intricate detail that makes these props so impressive. Tickets must be pre-booked at www.wbstudiotour.co.uk or by calling the Studio Tours Visitor Services Team on 0845 084 0900 and cannot be bought at the attraction.