"I will f**king gut you! I will make you bleed. Pain. Pain. A lot of pain."
That's Tim Kennedy -- UFC and U.S. Army Special Forces vet -- telling all the internet trolls what he's gonna do to them for spoiling "Star Wars: The Last Jedi."
Tim's a HUGE Sci-Fi guy ... but says he still hasn't seen the movie 'cause he's too busy being a badass in the desert.
Kennedy tells TMZ Sports he's pissed 'cause he can't touch social media -- "there's a bunch of a**holes out there trying to ruin it for people like me!"
So, if you spoil the party -- like UFC contender Colby Covington did on Thursday -- Tim says he's literally gonna cut you open and let you bleed out.
Yeah ... the force is strong in this one.