Nightmares are the primary enemy in Feel The Snow. They appear when the in-game time turns to 0:00
(also visually indicated through the light level darkening) and stop spawning/disappear when the time turns to 6:00. They will not spawn in houses, but can and will enter if the door is left open. They will not attack other NPCs or mobs.
Nightmares come in a variety of sizes. The smallest Nightmares deal 15 damage per hit to the player without any armour. The attack animation of Nightmares can be cancelled by attacking them, so if the player can get a rhythm of attacks in, the Nightmares are no threat. Nightmares have 50-52 health.
Nightmares are a key part of advancing as they often drop item recipes. These item recipes allow the player to craft better items such as swords and armour. There is a chance that the first few Nightmares you kill will drop a "Mysterious note." Your journal will tell you to read it, which will lead onto a quest to further the plot.It should be noted that Nightmares are faster than the player's walk speed and match their run speed.