Epsilon is an Altered. It is unknown whether he has had any contact with any others of the Altered, or believes himself to be the only one.
Epsilon has very thin bristles of a dark material rather than hair, and only a sparse amount of it. His mouth is fused closed and can hardly be seen. His back bulges oddly as his spine and his entire nervous system is coated in a thick substance, possibly the 'ichor' or 'Slender Man Slime'.
No longer working for Slender Man, nor working against him, Epsilon prefers to stay away from the eldritch, hoping that by hiding his past can be forgotten. Unfortunately, his altered appearance may limit this.