Making superhero movies can be a dangerous proposition, and not just because of the crazy fans. While shooting Guardians of the Galaxy, Zoe Saldana almost broke Chris Pratt’s ribs because he forget to wear his protective padding during their fight scene on Xandar. This is just one of the facts packed into the latest episode of You Think You Know Movies, which heads back to outer space with the Guardians of the Galaxy!

We all know that Oscar-nominee Bradley Cooper provided the voice for Rocket Raccoon, but that was provided in a voiceover booth by himself. To help the actual actors on set, director James Gunn’s brother, Sean (who also played Yondu’s pal, Kraglin) was the stand-in. He wore an all-blue spandex suit and walked hunched over so he'd be the size of a raccoon. And for all that work, he was replaced with a CGI raccoon.

“You Think You Know Movies?” is a ScreenCrush original series that dives deep into the cinematic worlds of your favorite movies and freeze frames a few tidbits you might not have known. We’ve already tackled Star Wars, The Avengers and Spider-Man, but now, it’s time to catch up with our favorite losers in this Guardians of the Galaxy video!

Watch more installments of ‘You Think You Know Movies?’ below and let us know what movies we should cover next.

Check Out the Coolest Marvel Movie Easter Eggs

More From ScreenCrush