Shadow Rat's appearance is similar to that of the RAT from FNAC 2. He has hollow eyes and jagged teeth. Much like the RAT from FNAC 2, Shadow Rat's forehead is stitched together. The sprite of Shadow Rat looks more similar to that of Monster RAT, seeing as how you can see his eyes when he is facing south.
Shadow Rat also has another form only seen in the "Shadow Challenge." The Shadow Challenge only includes Shadow Rat, a purple, shadowy form of the original Monster RAT. He has no pupils, and is much more menacing than the Monster RAT, with a pose more elegant and pronounced than the Monster RAT's hunched over, beastly nature.
Shadow Rat will sometimes appear in the "darkness" within the Deepscape if you walk for long enough. He'll appear as a silhouette just enough to see the outline. If you run while Shadow Rat appears on-screen, he'll chase you until he catches you or you reach a "light path" again. It is possible to avoid his detection, as long as you walk behind him or pass away from his line of sight. If you manage to escape to a light path while he chases you, he'll disappear back into the darkness.
The Shadow Rat of the "Shadow Challenge" behaves exactly the same as the Monster RAT from previous nights, except unbelievably fast when running to the hallway, closet, or dresser, giving next to no time to use the tape recorder. He will distort the tape recorder just like Monster Vinnie and Monster RAT, that is, if you're able to be quick enough to use the tape recorder properly. He takes much longer to chase under the bed, and will dodge your light much faster, albeit still moving his head in a triangular pattern. If killed by Shadow Rat on the "Shadow Challenge," his jumpscare appears, being an animated still of Shadow Rat's head glitching, similar to that of Nightmare of FNAF 4.
Strategy (Shadow Challenge)
Shadow Rat's "Shadow Challenge" is by far the hardest night to beat in the entire game, and rightfully so, however it isn't that combat against him is difficult. The difficulty comes in with Shadow Rat's speed. Shadow Rat is the fastest enemy in the game, from going from door-to-door, to moving his head in combat, to going under the bed and popping back up, and even returning after combat is over. Don't expect to ever have a second without combat in this challenge; you'll be fighting more than you'll be resting. That being said, here's a few tricks you can use to get an edge on Shadow Rat:
-Shadow Rat moves the fastest in the game, but as long as you can master Monster RAT's triangular movement cycle when in combat, then Shadow Rat will be easy enough, as long as you have fast reflexes to boot.
-Shadow Rat moves instantly to another door when you shine a light on them. To help keep them at bay for long periods of time, continuously shine your light between the "hallway and dresser," or the "closet and dresser." This way you'll have two of the three locations constantly checked, with the third location saved for if Shadow Rat is in neither of the two locations. The best spot for this is the "closet and dresser," because hitting Shadow Rat by the hallway door when in combat is easier than either of the other two locations.
-Either keep tending to the tape recorder if you're skilled and fast enough to do so, or completely abandon it. Not only can Shadow Rat distort the tape recorder while under the bed, making hearing his movements to quickly shine your light on them more difficult, but it's also very risky since Shadow Rat moves so quickly. Choose your poison, and stick to it.
-The trickiest part to beating Shadow Rat is shining your flashlight on their face when they pop out of the bed. You have literally two seconds to shine on their face. Any more than that, and Shadow Rat will attack you. Try practicing how fast and precise you can do this process on Night 5 as practice, and once you feel confident enough, try, try again! This isn't really necessary, though, if you're already skilled at doing the motion.
- Shadow Rat made his first and only appearance in FNAC 3.
- Shadow Rat has many features similar to that of The RAT in FNAC 2, most notably the stitched forehead and the hollow eye sockets.
- Shadow Rat appears to be a hallucination of Mary Schmidt, since the only way to find him is to go to the Deepscape. This is the only place the Shadow RAT is ever found.
- Supporting this, in addition to the ambiance played on all nights, Shadow Challenge has sirens blaring distantly, this only seen rarely on Night 5 from among the other nights. The alarms may allude to the incident in which Mary's brother was attacked by The Rat. Shadow Rat could be how Mary envisions the spirit, similar to Nightmare in FNAF4. This is only speculation.
- Emil Macko says that Shadow RAT is the RAT himself, haunting Mary's nightmares in a noncorporeal form, much like Shadow Candy.
- Shadow Rat has no visible relations to Shadow Candy from FNAC 2. However, they appear beside each other in the Thank You! screen.
- Shadow Rat's jumpscare from the "Shadow Challenge" is very similar to that of Nightmare and Golden Freddy's jumpscare from the FNaF Series, being an animated still of Shadow Rat's head before exiting to the extras menu. The only difference is that Shadow Rat's jumpscare is animated, while Nightmare and Golden Freddy's jumpscare is not.