Black Ops III Revelations Zombies - Passive Zombie - Bug, or part of a Super Easter Egg?

Not sure why other gamers aren't talking about this. Is this just me? Whenever I train in Kino, I get a weird passive zombie spawn in. It goes up on stage and just chills. If I leave the area or it's the last zombie of a round, it'll collapse to the ground. Not sure if this is bug (if it's just in my game), or maybe part of a Super Easter Egg step. Does anyone else experience this zombie?