I updated my theory that The Mimic is wearing whats left of Afton, I think this becuase the jaw's are very similar, and their left foot is the same. Also, the Mimic's top part of their right leg looks very similar to the endoskeleton's legs of Burntrap. There are also veins on the body, possibly from Afton. On the Mimic's bottom part of their left leg, there are what looks like some springlocks. Both their hands are very similar too. I will work more on it later, but that's what I got for evidence so far.