By Clark Collis
Updated September 21, 2016 at 04:33 PM EDT

Director Mike Mendez has made one movie about a big ass spider (2013’s Big Ass Spider!) and another about over-sized “lavalantulas” (2015’s Steve Guttenberg-starring Lavalantula). But on his new action-horror-comedy Don’t Kill It (which premieres at the upcoming Fantastic Fest), the filmmaker got to work with a real larger-than-life character: Rocky IV and Expendables actor Dolph Lundgren.

“The story is about a remote Mississippi town that is invaded by a body-hopping demon,” says Mendez. “It jumps into the body of the last person who killed it, and it is making its way through this town, decimating the inhabitants. Our demon-hunter, Jebediah Woodley, who is a kind of a rogue exorcist, played by Dolph Lundgren, comes to town, and he is the only one who can stop it, because he’s got a history with this demon. And many people die!”

Mendez began pre-production on film six weeks before Christmas, 2015. The problem? The whole thing had to be shot by the end of the year. “I went into the biggest whirlwind I’ve ever gone into, essentially having two weeks to prep the movie, landing in Mississippi, and then going for it,” says the director. “But I really want to credit Archstone Pictures, that financed the film, and produced it, for really supporting me, and letting me go nuts, and have fun with the insanity of it. They really had my back. There were many times I was kind of looking at them like, ‘Really? You’re going to let me do this? Okay, cool. I love you guys.’ It was an insane, insane shoot. But I’m amazed at what we accomplished in that short time. I really think it came out great.”

Unlike many of the roles Lundgren has played before, his demon-hunter has a lot to say for himself.

“I think Dolph saw an opportunity to really show a different side of himself,” says Mendez, whose film also stars Kristina Klebe (Rob Zombie’s Halloween) as an FBI agent. “I think there’s more dialog in this movie than all of his films combined in the ’80s and ’90s. He’s got pages, and pages, and pages, of dialog. That really excited him, because he is a smart guy. He’s got a 160 IQ, he’s got a master’s degree in chemical engineering. I think it was really great for him to not play either the crazed psycho, or the silent tough guy, but play a kind of clumsy, backwoods, whiskey-swilling drunkard.”

The collaboration was a dream come true for Mendez, too. The director owns an action figure of the actor’s Rocky IV character Ivan Drago and a toy version of Castle Grayskull from the Lundgren-starring Masters of the Universe. “I make no effort to hide that I am a hardcore geek and, much like The 40-Year-Old Virgin, have a massive action figure collection,” says Mendez. “One of my favorite moments in the production was having Dolph come over to my house. I got some amazing photographs of him holding his Ivan Drago figure, reuniting him with Castle Grayskull. He was a good sport. He was like, ‘Oh my god, what a little geek! I love him!'”

Don’t Kill It will receive its North American premiere at Fantastic Fest on Sept. 24 at Alamo Drafthouse South Lamar in Austin. You can see the mayhem-packed trailer for Don’t Kill It, here. And you can see exclusive images from the film (plus, a shot of Lundgren being reunited with Castle Grayskull), below.