Possible shape-shifting mouse(probably not hallucinating)

Put this in other cause I have no clue what this would be

My cat was just very interested in a box and making squeaky noises at it so I went to see what she liked about it do much and there was a mouse inside. A real living mouse, it was moving around and hid under one of the cardboard flaps. I went and grabbed some gloves to pick it up with so it wouldn't bite me and put it outside, I came back wearing the gloves, moved some stuff out of the box and pulled up the flap to grab the mouse and it wasn't there and there was a little white mouse cat toy which most definitely was not the mouse I saw. I checked everywhere inside the box and just outside of it and I know it didn't run away because the sides of the box are too high and too smooth to climb plus my cat would've audibly freaked out if it did because she was circling the box the entire time. If I go back tomorrow and that toy mouse isn't there I'm gonna flip the fuck out because somewhere in my house there is a magical shape-shifting mouse, yes this is a real story that just happened, yes I'm sleep deprived, I might've been hallucinating but I DID NOT hallucinate the cat freaking out the cat does not lie