Bad, Bad Rubber Piggy is a great episode from the middle of season one. The main premise for the episode is that Zim has created a device which can replace an item in the past with an item from the present. He tries to send a robot into the past to kill Dib (Terminator anyone?) but finds that the robot is not an acceptable item for the temporal replacement. What IS an acceptible item, though, is GIR's toy rubber piggy. Zim begins to attack Dib with piggies throughout his past…but that which doesn't kill Dib only ends up making him stronger…

This episode had one of the first squid sightings - scientists demonstrating the potential problems with the temporal replacement device sent a giant squid back in time to replace the bran in Breakfast Chunks. Of course then Breakfast Squids caught on and the world has never been the same.

My Favorite Moments:

Seeing GIR's head explode as he tried to understand the paradoxes involved in changing the time-line and watching the geyser of rubber piggies was funny as was GIR's emotional attachment to each one.