When Middle Earth's spacetime was being woven, Ungoliant showed up. No one made Ungoliant. No one knows how it showed up. It's like saying 'God said "Let there be Light." And there was Light. And something saw the Light. And hungered.'
Madness string 112091
Have you heard about Quantum Immortality? Basically, from what I understand of it, in a near-death experience your active consciousness transfers over to an alternate reality where you lived. The others won't follow though and will just witness the reality where you died but you have already transferred so it doesn't concern you. It's the best I can explain it but what I can say is I definitely know that feel. There were multiple times in my past where I was in a near-death situation and I was one step away from passing on, but still I lived, or at least my consciousness is still alive despite the odds.