Peacemaker star Robert Patrick explains why James Gunn didn’t cast him in Slither. Gunn is now best-known as a director of huge franchise films like Guardians of the Galaxy and The Suicide Squad. But the filmmaker first burst on the scene with a much more low-budget horror film called Slither.

Hardcore horror fans of course well-remember Gunn’s Slither, the 2006 splatter film about an alien parasite invading Earth. Starring Nathan Fillion, Elizabeth Banks, Gregg Henry and Michael Rooker, the gross-out movie failed to make back its modest $15 million budget at the box office, but did go on to become a cult classic. Having established his signature horror-comedy approach on Slither, Gunn went on to direct 2010’s superhero movie Super before signing on to guide the Guardians of the Galaxy franchise for Marvel. Gunn later branched out to DC with The Suicide Squad as well as 2022’s HBO Max streaming hit Peacemaker.

Gunn’s Peacemaker of course features an ensemble cast headed up by returning The Suicide Squad star John Cena. But indeed Cena isn’t the only Peacemaker actor who crossed paths with Gunn on a previous occasion. It turns out White Dragon actor Patrick encountered Gunn years ago too, when he tried out for a role in Slither. Appearing on Inside of You with Michael Rosenbaum, Patrick discussed why Gunn elected to pass him over for a role in his 2006 cult film:

“James [Gunn] and I were trying to figure out where we met. When we were doing Peacemaker. He alluded to the fact that possibly I had read for him for Slither. And he gave it to Rooker cause, James and his inevitable way of making you feel good, he said something off-hand like ‘I think you were too good-looking.’ It was the sweet thing to say.”

Rooker of course starred in Slither as the amusingly-named Grant Grant, a rich man who ends up as a host for the movie’s alien parasite after it arrives on Earth. Unfortunately for Grant (and perhaps Rooker), being infected with an alien parasite leads him to transform into a horrific and slimy monster. Rooker clearly took no offense to being subjected to such a transformation, achieved via elaborate prosthetic makeup effects, as he later returned to star in more movies for Gunn.

Given the makeup work required to turn Grant Grant into an alien monster, maybe Patrick is actually lucky he missed out on starring in Slither. That said, it’s not as if Gunn went easy on Patrick in Peacemaker, where he had to play a hateful white supremacist who transforms into the supervillain White Dragon. But actors obviously know that, if they go to work for Gunn, there’s a good chance they’ll be asked to do some pretty extreme things. Going too far is obviously Gunn’s trademark today, and it was already his trademark when he made Slither. Rooker of course was a fine choice to play Grant Grant in that 2006 splatter classic, but Patrick would have been solid casting too. Who knows the real reason Gunn elected to pick Rooker over Patrick, but his explanation is definitely a charming thing to say. And ultimately it worked out as Patrick got to work with Gunn anyway.