The declaration of dread.
Humans born in the machine, with complete understanding of the machine and the ability to pilot these massive machines as if they were their own body's.
They collect old tech and horde scrap metal, to improve their body's or to create offspring which they can do by artificial means or by forcing others to become machines and serve the old one spreading the old ones law, that all will serve the machine one way or another.
Their origins are unknown, but there have been some unconfirmed accounts from unreliable sources that they have seen massive machines crawl out of the oceans.
But regardless of their origins they are an extreme threat.