10 Disturbing Video Game Secrets Hiding In Plain Sight

W. D. Gaster is the mysterious entity that has a rare chance to appear in the game. According to the hints you find throughout the story, he used to be Asgore's royal scientist before Alphys, who, due to a fatal error in his experiment, was torn between time and space and mostly forgotten by everyone.

This said, the player can have multiple encounters with Gaster without even doing anything.

The spectre can appear randomly in a number of locations, most noticeably the rooms of his old lab, and give you quite the fright with his unsettling appearance and lack of a hitbox that allows him to phase through the player while making unsettling noises.

You don't really know who Gaster is when these events happen to you, but once you get the context, the encounters become only creepier.

There's just something morbidly fascinating about Gaster, from his looks to his backstory, that makes him stick out more than even Flowey and his abstract horror boss fight at the end of the pacifist route.

You know there's something seriously wrong with a character when it scares you more than a collage of human eyes and teeth...