Venominu's Bloodbath

It is called "Mountain Stalker". It spawns behind mountains and stays hidden, with only its head (and a small part of its tail) visible. When spotted, it quickly hides itself.

By default, it can appear as early as Day 1.

When you go to sleep, you have around a 20% chance of triggering a Nightmare event.

During the event, a disturbing image of the Bloodbath appears, accompanied by a strange sound and several lines of text. The game is paused while the event is happening.

There are 5 different phrases/conversations:

Phrase 1:

“You won't be alive for much longer...”
“Enjoy it while it lasts...”
“Wake up”

Phrase 2:

“You cannot escape from death”
“You cannot escape from me...”
“I will always be here”
“Close to you...”

Phrase 3:

“I pursue you even in your dreams”
“I always know where you are”
“I am coming”
“There are no places you can hide.”
“Not from me.”

(Yes, “There are no places you can hide. Not from me.” is a reference to the Doctor from Poppy Playtime.)

Phrase 4:

“This isn't a dream.”
“You can't run away from me.”
“You're already mine...”

Phrase 5:

“I will be here until your last breath”
“I am coming...”