Terrible Prologue. Great first chapter. You're not a bad writer but you mixed some elements of a prologue with a beginning.
A prologue is meant for explaining the main character and the setting.
The should be nothing of the plot in the prologue.
The middle (the moon and stuff) is great for a prologue but the beginning (the shriek) and the ending(The Krakzah) is suspenseful, but it should be part of the main story not the prologue.
This would be a great back cover summary to make people want to read your book ( if you decide to make it one).
...Holy crap did I just write an essay? lol. I'm gonna add you I want to read more of this, but consider editing.