Mechanic: Check works like Ambush, but it is able to rebound 4 to 12 times as if it's double checking. Check always appears 20 doors ahead, but only opens the exit to the room you're in. Check is also 1.25x as fast as Ambush. The thing about Check (besides the amount of times he rebounds) is that it, unlike Rush and Ambush, checks every corner, basement, attached room and vent, leaving beds and closets as your only hope. Example:
Guiding Lights messages when you die to it:
Message #1: You died to Check...
It likes to come back to make sure it's victims are dead,
Use what you learned from Ambush!
Message #2: You died to Check again...
Don't use corners, vents, basements and other rooms to your advantage.
Jumpscare:
Another thing about Check:
Check cannot spawn in room 49 and Room 99, but it can spawn in rooms that have eyes on the walls.