Zeus, the king of the gods in Greek mythology, is famously wicked. He lies and cheats, especially when it comes to tricking women into infidelity. Zeus consistently doles out harsh punishments to those who act against his will - regardless of their merit. And although some characters from Greek mythology arguably deserve to be put in their place, most of Zeus's punishments are way out of line.
The messed up things Zeus has done usually involve extreme circumstances, and humans are not his only prey. The deity is responsible for some of the most over-the-top punishments in Greek mythology.
Before marrying Hera, Zeus was in a union with a Titan named Metis. Things were going well until a prophecy was spoken to Zeus that said he'd be overpowered by one of the two children he'd have with Metis - the same way he overtook Chronus.
To keep from having children with Metis, Zeus convinced her to turn into a fly and then he ate her. At the time, Metis was pregnant with Athena, and when the girl was born, she had to be split out of Zeus's head by Hephaestus. Metis, however, was never heard from again.
Prometheus took fire from the gods and gave humans the gift of heat and light. Zeus wasn't pleased with Prometheus for his act of pilfering, but more than anything, the god was angry that someone would defy his will. To punish Prometheus, Zeus chained him to the side of Mount Caucasus.
But Zeus didn't just chain Prometheus - the king of the gods added a little twist to his retribution. Zeus ordered an eagle to peck out Prometheus's liver every night. Then, his liver would revive itself, and the eagle would come back and start the whole thing over again.
Zeus designed Pandora to be a burden on humanity. After she was created by the gods, Hera gifted Pandora with a thirst for knowledge, and then Zeus gave her a box and made her promise never to open it - something he knew she couldn't do.
Unable to curb her curiosity, Pandora opened the box and unleashed everything evil into the world.
Io, the princess of Argos, was a beautiful young woman that Zeus tried to woo in a multitude of ways, but she never accepted his advances. Rather than move on, Zeus turned himself into a cloud and hooked up with to her.
When Hera found out about the interaction, she turned Io into a cow and sent a stinging gadfly to follow her everywhere she went to drive her mad. Io ended up fixed to a tree, guarded by the hundred-eyed dog Argus. After Io wandered to Egypt, Zeus turned her back into a human.