James Gunn gave Nathan Fillion plenty of room to play with his Slither persona

Perhaps the best part about Gunn letting his actors really dig into their characters and indulge their ideas is that he also knows how that plays into the feature film as a whole. While filming "Slither," Fillion thought his character was something of a prankster, showing wisdom in tough times. Instead, Pardy is the straight man of everyone's madness, and his jokes ended up cementing his everyone's nature. Fillion remembers talking about filming with his friends while playing video games (he's a "Halo" fan!) and how much fun he had playing with his own character:

"I think it's really great to screw up your own character, and everybody was doing that. I was like, 'We're doing a very funny movie, I have a very funny character. . We seem to be making a lot of jokes" but seeing the movie I found out I was the straight man and I just didn't know that. I think that's great and I think that's James Gunn. That's the story, that's the idea, that's the tone and I think that's what he created."

Gunn has since directed all sorts of movies, including the more family-friendly "Guardians of the Galaxy" for Marvel and "The Suicide Squad" for DC, but his directing sensibilities have remained the same. His actors are encouraged to dig deep into their characters and express themselves, and he seems to view filmmaking as a truly collaborative effort. There's a warm, squishy heart at the center of almost everything Gunn does, and the way he works with his actors probably has something to do with it.