At the risk of sounding like the total nerd that I am, in the 30th or so repeat of the first episode of Futurama, I noticed something... Guess who saw Nibbler's shadow right when Fry falls into the cryogenic freezer thingy? That's right, me, I saw it. Now you know. I mean, what, were they actually thinking the story through from the start as opposed to just coming up with things randomly?
???
Maybe it was Flesh Gordon!
Flesh Gordon? Sounds like a name a cheesy porn star would use.
In any case, I'm guessing that the producers of Futurama wrote many storylines before even presenting the show to Fox, so that if it did get picked up, they'd have lots of episodes for the first season already written.
That's usually the way they do things.
Flesh Gordon was a cheap 70's porno ripping off Flash Gordon, It had all the exposure of a porn.
Just with space battles and cheap laser battles, The bad guy was called Emperor Wang from the planet porno.
The Lost Skeleton of Cadavra is a better movie.
But nibler was on another planet when they found him, not earth
There is an episode later on which proves that the reason Fry fell into the cryogenic freezer is because Nibbler was actually hiding under the desk and when Fry leaned back, Nibbler pushed him over the rest of the way. Nibbler even ordered the pizza under I.C. Weiner to get him to go to the cryogenics lab.
Why? Well, I could tell you but then I'd ruin the episode for you, and that is a particularly funny episode in my opinion.
Yeah, there's this whole... thing about that. Nibblonians live long and are celebrated poopers you see.