Keep your "Cloverfield" and "Super 8" monsters. For all the complex cinematic creatures on the market today, there's no beating the old-world horror of a headless naked man with a face on his chest.
Yes, consider the blemmyes, a race of 8-foot (2.4-meter) tall monsters said to roam the wilds of India and Africa. History's Pliny the Elder, Marco Polo and Sir John Mandeville all reported sightings in their travels -- and even the revered St. Augustine discussed the monster in theological discourse [source: Williams].
Don't confuse these blemmyes with the actual nomadic tribespeople of southern Egypt. Those guys posed an actual threat to the Roman Empire, while these guys are firmly planted in the realm of fantasy. Blemmyes became something of a standard in medieval monster manuals, where they eventually absorbed cannibalistic tendencies as well. It's all quite fitting for a creature whose head -- the spiritual center of its body -- has sunk down into the very pit of its guts [source: Mitmann].
Modern blemmyes are even ghastlier. In the "Medieval Bestiary: Anthropophagi," a role-playing rules supplement for Dungeons & Dragons, we learn the creature's tiny brain rests "slightly behind the groin encased in a strong pelvic cavity" [source: Guill and Raynack]. The authors also describe them as cannibal corpse-herders who march in the wake of rampaging human armies.
Elevator pitch: In the modern day Middle East, a blemmye tangles with U.S. Special Forces soldiers when it cleverly disguises itself as a headless corpse -- all in order to gain access to the all-you-can-eat cadaver buffet we call a morgue. Think "The Hurt Locker" only with smiling monster bellies.