We were hunted by the mask

so uh yeah i made a full on video about this before i realised that i should probably be wary about what's causing this strange bug? we call him the man in the mask because he's not a normal mimic at all. i have a video on youtube with some unedited footage of him.
none of us played modded.
https://youtu.be/5vWBOWGjl64