Nightmare He/Him Resembles: Fear Weak, but extremely fast Mechanic: He will appear in hiding spots (1/4 chance), and if you hide in a spot where Nightmare is, he will zoom towards you and make you hallucinate different entities. Hallucination entities can be any entity except for doppel and mime. The hallucinations make you do the opposite of what the normal entity would want you to do (Aka: For Hallucination Slight, You Would Have To Look At It) Also, normal entities can spawn at the same time as the hallucination entities. If you fail to do what the hallucination tells you to do, Nightmare will instantly restart your run.
Dream She/Her Resembles: Sloth Slow, But Very Strong Mechanic: She appears in a random room, sleeping. You have to crouch and slowly walk to the next door. Fail to do so, and she will wake up and slowly chase you, making your screen flash colors until you get to a saferoom.