Slime is a huge part of Nickelodeon's identity and it all came about by chance. They were filming a scene for 'You Can't Do That On Television' where they were going to dump food scraps from the cafeteria on a kid's head. Problem was, they ran out of time. Canada's child labor laws were very strict so no one was allowed to go even one minute over the limit. When they came back the next week and picked up filming where they had left off, the bucket of food scraps had been overtaken by mold. Green slime was born and became a major part of the show. When Nickelodeon started broadcasting it in the US, it became their most popular show. They started using slime in other shows and it never stopped.