What is the Deadliest Machine of All-Time? (Heavyweight Division, Round 3)S

Not surprisingly, Megatron easily took another heavyweight round over Marvel's Sentinel. So we are upping the ante in Round 3 with a robot so horrifying, just thinking about it will give you nightmares for weeks.

Oh yes...it's Mega Maid from Spaceballs.

Stay tuned for the fourth and final rounds of the Heavyweight and Humanoid class battles later today. The winners of these final division battles will be pitted against one another in a winner-take-all, inter-divisional robo-superfight on Friday. Cast your votes and feel free to suggest a new opponent in the comments.

This tournament poll of the world's deadliest robots was proposed to us by our friend PW Singer, author of Wired for War: The Robotics Revolution and Conflict in the 21st Century which we covered last March. Stay tuned for more of the tournament, more from Singer, and for more scary-ass robots wreaking havoc on fleshy humans and metallic adversaries alike.

Machines Behaving Deadly: A week exploring the sometimes difficult relationship between man and technology.