Okay, I admit it. I was captivated by the John Lewis Christmas commercial and wondered, “How’d they do that?!”

Creativity went behind the scenes to find out. I’m glad they did.

Love it or hate it, John Lewis’s Monty the Penguin holiday ad is an unstoppable seasonal juggernaut, with YouTube views now exceeding 17 million. One of the reasons for the appeal of the U.K. retailer’s ad is its realistic depiction of an Adelie penguin, created completely in CGI.

In this fascinating behind-the-scenes film from VFX house MPC, you can find out exactly how Monty was dreamed up, created and rendered. It’s full of interesting nuggets — for instance, Monty picks up the Lego bricks the way that real penguins pick up fish — as well as providing an insight into the film’s production, casting and more.