By the third meeting at the edge of the world, bitter outrage shattered the night. The shape shifters fought amongst themselves, raising chaos in the forest.

"How dare he!" the wolf cried, beside himself at the she-bear's death. "How dare that beast slay our friend and wear her pelt to warm his shoulders!"

"He has to die for his evil!" wailed the cat. She paced on her rock, tail swishing to and fro. The thought of her own beautiful fur sitting as a trophy on the naked creature's shoulders stirred the dread inside her. "It is the only way we can be safe!"

"Agreed," said the stag, tossing his antlers. "Who of you will rise to slay this evil creature? Who will see the end to the stone claws, to the traps, the fire, humiliation and murder?"

The shape shifters thundered in unison; even the trees granted their silent approval.

The horde stormed from the treeline in search of Nem's home. Far from harm in his den, Nem slept soundly beneath the she-bear's pelt beside the dying embers of his fire. He'd drifted asleep truly believing he'd killed the she-bear for his own good. Decorated in war-paint, he'd driven her from her home with fire, trapped her in his net and taken her life with a crude spear he'd crafted himself. The only part of Arka's plan left was to wait until morning for another attempt at convincing the others of his brilliance.

Sweeping through the grass in silence was the king cobra, leading a vanguard of snakes. They knew the naked creature in its den had a wicked bite, but their many mouths would make light work of poisoning him first. From the bushes the cat, the alpha wolf and his pack lurked. Their old friend Nem was swift on his feet, but inside the cave he was trapped with nowhere left to run. His stone claws would inflict damage if he had time to grab them, but he would be surrounded, and where one shape shifter might fall victim to Nem, another would seize the opportunity to attack. The ox, the stag and their herds gathered side by side as a barricade at the rear, if, for some unforeseen stroke of luck, the naked shape shifter should be immune to venom and able to evade the predators' attacks. While the creature was strong, his flesh was still as fragile as a summer berry's, and he would not survive the stampede should the last stage of the extermination demand it.

The birds wheeled above them all, flittering amongst the stars as spectators in the void. For those particular shape shifters they gleaned no pleasure from doing the deed, only from the sound of Nem's last song as it filled the air: the blood-curdling scream of the unsuspecting creature being torn and twisted limb from limb.

Arka was nowhere to be seen.

Once Nem was dead and devoured, the shape shifters were happy.

For a time.

Though content they had rid themselves of a being whose existence only served to demean them, the error of their ways soon took root in their minds. They kept their regret locked away and did not discuss their dreadful deed again with any of their fellow shape shifters. Whenever they recalled the naked creature's last moments they felt no joy in seeing the horror on his face, and it only intensified the dismay they felt for their own imperfections. No amount of birds could ever sing quite as beautifully as Nem; the seal would never be at home on the land as he was in the water. The cat could not start her own fire to keep herself warm on the mountains in winter and the wolves could not cultivate wheat when the hunts failed.

The creature they had murdered had shown them their own limitations and weaknesses, not out of spite, but through example. He led a life that meant he was always warm and fed, and that whatever obstacle or danger he might face, he was, if not prepared for, equipped to solve. In their misunderstanding and jealousy they had killed the only shape shifter to have achieved everything they had ever needed within one skin, without ever asking him how he'd done it.

Had those not been the words of the she-bear?

Some years on, after learning of Arka's deception, the cat, the wolves, the deer and many others all vied to recreate the form that Nem had crafted for himself. It took many attempts, no less than Nem, before their familiar shapes could begin to mould exotic features. As it happens, the origins of history's fantastic mythical beasts – manticores, chimeras, griffons and the like – emerged from this era of shape shifting experimentation.

Their first success came with the formation of two arms and two legs, and following that they shed their fur coats so that they might swim. They taught themselves to chatter and sing, but their voices were guttural, sometimes hoarse, and some were better than others. Their best attempts at shifting to Nem's magnificently crafted skin only produced small, fragile creatures that could not run as fast, nor jump as high. They could not dig with their pathetic claws and instead relied on tools for the task. They could not bite with such small teeth, and thus their tools became extensions of the fangs they had lost. It took thousands of years before the shape shifters of old even unravelled the secrets of starting and containing a fire, and many more before they learnt to build traps or cultivate the land so that they might grow sustainable food.

So obsessed by the ideals set millennia before them, the shape shifters soon forgot how to change forms at all. In time, the knowledge to shift skins became lost and all that remains today of those who imitated Nem's accomplishments are a species of flawed, two-legged creatures without fur, without claws, without fangs, and without any idea of the entities they once were.

Me. You. Every human in every street around you is the product of survival, betrayal and vanity.