Maybe a plague of unknown animals, digging into graves and feeding on bodies. They climb out of the ground to recreate the dead. The vocal cords emulated through the throats of monsters, a high screech that blends back down into lower decibels to sound like a long dead grandfather. A twisting undulating mass of the creatures stretching into an arm, the end a giant ball uncoiling like the head of a medusa.
I picture human shaped things covered in sheets walking strangely, some losing sense of the anatomy of humans and contorting, stretching, pulling apart into nightmarish abstractions of what resembles a person. The sheets wrapped tightly like skin around them, intended to hide what is underneath, writhing and pulsing in and out as the eels coil through each other in the shape of man.
It ends with the extinction of the human race, an unimaginable number of the creatures combined into billions of human designs, some far beyond recognition. An insane parade of creatures imitating people, all traveling towards one destination. A pilgrimage to someplace in Africa, perhaps the Middle East. The most ancient of human remains, recreated and calling to the others. A siren sound that shatters through the sky, the weather deforms around the destination. Storms grow in intensity around a vast towering structure. All the creatures build over one another, higher and higher into one gigantic shape. The human designs break apart into almost spider or crab like anatomies, the size of trucks, long limbs stretching over one another, climbing higher and higher. Lightning flashes on the miles high collage of twisting pulsating eel like creatures. Eventually it all stops moving, all of the grotesque creatures become solid as stone. The storms disappear, leaving a Godlike structure reaching miles into the sky. But somewhere inside something is moving, scratching, banging, trying to make its way out.