Once upon a time there was a little robot with big ideas.
He collected up all the non-biodegradable waste materials he could find and used them to build himself up.  There was no shortage of junk to be found and he grew bigger and bigger until he was taller than the tallest tower blocks.
It was then that he realised that he had to get to the root of the junk problem. He soon found that the humans could be recycled too...