The Conquer Robots

Devastating Conquer Robots are planning to threaten the next city they see. They were once so poor that someone made a mistake of helping them: a scientist named Robert. Robert made the Conquer Robots drink the wrong potion, and this potion upgraded the conquer robots, making them very big, strong and powerful. They grew 12 times bigger.  

They were so strong that even the Greek gods couldn't defeat them. But the potion also made them evil. They destroyed cities, enslaved people, and even sometimes fought their own kind.

But after a month or two, the potion lost its potency and the Conquer Robots turned back into their old poor selves. Robert the scientist learned his lesson and told himself that he would never help any robot again.