In all the recent furor over pink slime, we've completely neglected green slime! Here is former You Can't Do That On Television co-creator Geoffrey Darby describing the origin of the green slime that became synonymous with Nickelodeon:
We went to the cafeteria and got them to give us a bucket of slop.
We said, "We want you to take all the stuff that's left on plates over the whole day and put it in this bucket." And then we were going to dump it on the kid so that it looked like if he pulled the chain, sewage would come out.
We didn't get around to shooting the scene because you can't go into overtime with children. It's against the law. If you don't get the scene, you don't get the scene. We didn't get it shot.
So we put the set up again the following week to shoot that one scene...
The prop man came to me - literally, this is a completely true story - and said, "There's a problem." The problem was that he didn't get a new bucket of slop. He just kept the old one back stage. There was about eight to ten inches of green crud. Growing. It had grown on the top of this bucket of... stuff. There was mold.
So, we had to get the scene, right? We couldn't get more slop, because we couldn't! I said, "Dump... it... on... the... kid... anyway."
And that's how green slime was invented.
Mathew Klickstein of Splitsider has been doing a series of posts on the origins of early Nickeldeon shows - "Nick of Time" I guess is the title - including interviews with the people behind Doug, Pete & Pete, and Clarissa Explains It All. You should definitely give them a read.