In phase 6 you will come to one of them bronze colored doors where you need to find 2 levers to unlock it. In one of the rooms with a switch you see a furnace in the corner with a container of body parts next to it. On the furnace door, look closely and you see Freddy's infamous red and green striped sweater hanging on the furnace door. Look closer and see his hat on the floor next to it. Look even closer at the bin of body parts and you see a hand with a familiar knived glove sticking out. Not a cheat but still pretty awesome.