A new clip from Harry Potter Wizard’s Collection – the massive, complete box set – has been released, and in it we learn about how the crew designed and found a person big enough to play Hagrid.

We all know that the actor we usually saw on screen was Robbie Coltrane, but when they needed Hagrid to appear larger, they had Martin Bayfield fill in. When Bayfield was on screen, you would only see his back or lower half when standing next to other actors. Nick Dudman, the film series’ make-up effects supervisor, explains in the video below.

Also in the video were a few pieces of concept art for Hagrid which reveal plans for a slightly different looking character:

Harry Potter Wizard’s Collection will be released September 7.