Eventually, a bunch of these slaves finally decided they were sick of being treated like unfashionably old cell phones, and in 135 B.C. on the island of Sicily, the slaves revolted. Led by a self-proclaimed king named Eunus and initially armed largely with farm implements and kitchen tools, the slaves held out for three years before finally being defeated by Roman forces. Did I mention that Eunus could apparently perform magic and breathe fire?
Obviously, there are many ways this war could go if you were making it into a movie. You could focus on Eunus himself as a main character, although since his armies had a tendency to kill Roman women and children, you might have to do a bit of historical scrubbing. Or your protagonist could be a Roman soldier sent to defeat the slave menace, who maybe feels a little emotionally torn over the maltreatment of the slaves versus the fact that the escaped slaves are killing babies. Either way, you'd have a guy who could breathe fire, so you could make it work.
Recently, movieland has given us a wave of historical war movies about Greek and Roman times that carefully extract any traditional or mythological elements from the stories and replace them with "accurate" history. This is perfectly fine, assuming that you don't want your movies to have boring shit like "wizards" and "demigods," and instead really want to see people gazing seriously at each other under a heavy blue filter. Even the success of 300 didn't do much to buck the "history should be dull as hell" trend. Take these scenes from Centurion (2010) and The Eagle (2011):
Shown: the dark period of human history before the invention of the color red.