When there's no more room in the pit, the dead will walk the earth.
Since I'm talking about how perfect Masterforce is for Halloween, let's take a second to talk about Destroids. Destroids are Decepticon Zombies. No really, the Decepticons made a point to make an army of Zombies in Masterforce.
They even gave them uniforms.
Honestly, I have to just applaud this idea. I mean, let's think about this for a second. What's a better way to slow down the Autobots than hordes of humans that they won't want to harm.? Not to mention, considering the bulk of the Autobots transform into some form of car, that would really slow them down.