Rush takes on the appearance of a dark grey face encompassed by darkness. Parts of its face are distorted and it expresses a large open smile, showing its rows of teeth.
Rush will flicker the lights as a warning before speeding through multiple rooms and disappearing. Rooms that Rush has passed through will have their lights shattered and the room will fall dark, but it won't be as dim as dark rooms (i.e. Screech cannot spawn) and will not play the sound that plays when you enter a dark room. Rush will kill players when detected by its raycasting. Hiding while Rush is rushing through rooms will let the player survive. Rush will automatically open the door of the following room upon reaching the end of its route.