"Tekeli-li! Tekeli-li!"
Shoggoths (sometimes known as Shaggoths) are creatures which appear in H.P. Lovecraft's Cthulhu Mythos.
Description
Enormous beings who would measure some fifteen feet across if they formed their bodies into a sphere, Shoggoths are amorphous creatures composed of a malleable protoplasm, something akin to a colossal amoeba. They are capable of forming whatever organs or appendages they require for the task at hand, although their usual state is a writhing mass of eyes, mouths and wriggling tentacles.
Shoggoths have a tendency to scream a cry of "Tekeli-li! Tekeli-li!" over and over again. This sound is theorised to have been an instruction uttered by their former Elder Thing masters, or possibly an exhortation to greater effort.
It should be noted that while the "fifteen foot sphere" measurement is true of most Shoggoths, there are smaller and much, much larger variants of these beasts.
History
Aeons ago, when the race of alien beings known as the Elder Things came to Earth, they realised that they required a source of exploitable labour. Using their vast scientific knowledge, they genetically engineered the Shoggoths to construct cities, tend farms and perform a myriad of other tasks for them, their natural shapeshifting abilities making them perfect for working on both the land and at sea.
Originally created to be nothing more than a mindless workforce controlled through hypnotic suggestion, over the next few millions of years the Shoggoths slowly evolved a certain sentience, became dissatisfied with their place in society, and rose up against their masters. Whilst this rebellion was quickly put down by the Elder Things and their advanced technology, the destruction of the Shoggoths was by this point not an option; the Elder Things had come to rely too heavily on their creations for their civilisation to function without them.
Fast forward another few million years and the Shoggoths revolted again; this time, however, they were more coordinated and caught the Elder Things completely off guard. Unable to stop the advance of the Shoggoths, even with atomics and directed energy weapons, the Elder Things finally retreated to their last and greatest city, located deep in the Antarctic interior; this city, being constructed both on land and underwater, was the site of the last battle against the Shoggoths. Finally losing control of the landward portion of the city, the remaining Elder Things atempted to retreat to the undersea section, not realising that it was already infested with Shoggoths, and the last of Earth's Elder Things were destroyed, torn apart by their former slaves.
From then until the present day, the number of Shoggoths active on Earth has slowly dwindled to next to nothing, and in the modern age can only be found in the Elder Things' abandoned city in Antarctica, in the deepest oceans, and hidden away in the darkest, most inaccessible corners of the world.
The underwater race known as the Deep Ones have been known to make use of the services of Shoggoths (specifically a breed known as Sea Shoggoths), although what the terms of these contracts are and how payment is made is unknown.
The alien Mi-go have also conducted experiments with Shoggoths, performing mind-grafts on captured examples to produce a more placid and easy-to-control breed. These Shoggoths go by the name of ghols or ghol-things.