3. The Reverse Bear Trap (Saw, Saw VI, Saw 3D)

The reverse bear trap is the only trap to have appeared in more than one Saw film, and you don’t even get to see it properly set off until the third act of the final installment (and on the one person you didn’t want to see die). Still, the aftermath of the trap is particularly gruesome. It’s an instant death, but the seconds leading to the snap must be torturous.