The Revenant has been making waves in the movie world since its Christmas day release, particularly for the hyper-realistic scene in which Leonardo DiCaprio’s character is savagely attacked by a bear. However, as authentic as the grizzly appears, the now-infamous beast is actually a result of CGI. “There was no bear ever on set,” stuntman Glenn Ennis told Global News. “The closest a bear ever got to set (that we knew of) was at the Calgary Zoo.”

Ennis was one of two stuntmen who stood in for the computer-generated bear while filming was taking place, and was charged with portraying as convincing a grizzly as possible. “In rehearsals, I would wear a blue suit with a bear head,” he said. “Obviously that doesn’t make it into the film, and the CGI guys paint the bear in. Alejandro [G. Iñárritu] was adamant that the blue bear moved just like a real bear would move, and it was essential that it had the same nuances that a bear would have. Even though it was a big Smurf bear, it still had to be as authentic as possible.”

Read More: This Video Is the Only Cure for Watching The Revenant

The 51-year-old Vancouverite explained that the role often required him to spend quite a bit of time up close and personal with the film’s star: “If you notice the bear head in the picture, they wanted the bear mouth to be right on his lower back. I was supposed to grab his jacket with my hand to make it look like the bear’s jaws were pulling it. In order to have the bear’s jaw in the small of his back, basically my face was in his butt. My face was in Leo’s butt for a fair bit of time. I can see how that’s someone’s fantasy, but it wasn’t mine!”

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Write to Megan McCluskey at megan.mccluskey@time.com.