"KAAAAAAA!!!"
The fat prisoner let out a sharp cry as he lunged in Mark's direction. For someone who looked to be 300lbs (136Kg), the prisoner was quite agile. With about a hundred meters between them, Mark thought that he had enough time to react, but that turned out to be a miscalculation.
The prisoner was not in his right mind, and as if to hammer in that point, he went down and started sprinting on all fours. He crossed half the distance in just a couple of seconds and it looked like he wouldn't take more to close what remained.
Struck with panic, Mark turned to the Sergeant for instructions only to realize that he was gone. In that short moment, the fat prisoner reached his position and lunged at him, his mouth spread so wide that his jaws dislocated.
Mark jumped out of the way at the last moment, barely evading the bear-sized man attacking him. But of course, that was not the end of it.