 SCP-646 is a large, translucent gray, bloated creature measuring roughly 5.6 meters in length, weighing between 3400 and 3700 kilograms. At one end of its body is the approximation of a torso, with a prominent rib cage and a wide round head. Seven sets of three jointed limbs are located evenly spaced down the front of the body. A long series of utter-like organs are located between these limbs. The body tapers to a blunt point with a cloaca-like orifice, the entire frame heaving and shuddering irregularly. Lungs, hearts, and a digestive tract can be seen through SCP-646's flesh.