BtVS by Whedon and Mutant Enemy. Muppets by Jim Henson Productions. Stargate by Gekko Productions and others. This meeting is inspired by Muppets in Space. Main cross with Stargate later, for now it's just their version of Area 51.
Twisting the Hellmouth has a long set of Fic-For-All Prompts, in the format of "Buffverse Character & Crossover Character". Fill one, you get to post one for others to meet. This story fills one each chapter and is mainly about the loose connections that form between them.
Ethan Rayne was annoyed.
It wasn't enough that the Army had spent the last year-and-a-half poking and prodding him, now they had to throw him to the Air Force.
At least the cell was cushier... And his handset had been upgraded. Not the absolute worst way to spend his forced 'retirement'.
In the cell across from him sat the third-oddest demon he'd come across, but introductions would have to wait until his brand new warden had finished making sure he was 'comfortable'.
When the guards had left, the small blue creature sat up and turned to face Ethan.
The creature's eyes opened wider as it spoke: "Hey, you look human enough. Why did you throw you in here?"
Ethan replied, by way of his handset: "Threat to national security, and all that. How about yourself?"
"Just my rugged good looks... How come that thing has to talk for you? If you don't mind me asking."
"Kind of an enforced vow of silence. They implanted a chip which completely deadens my vocal cords. They're still intact, but very useless at the moment."
"Wow. So they must be afraid of your voice?"
"It's somewhat of a focus for my inner power. You wouldn't be able to shoot eye beams, or anything like that?"
"No, but I can squeeze my nose and make odd noises... Wanna hear?"
"Maybe some other time."
"Ah... That little thing must be pretty expensive if they had to import it from Britain."
"Actually it's supposed to sound like my original honeyed tones... At least it's better than the first few they gave me. The first one sounded too much like a telephone operator, the second one like Hal 9000."
"That must have been fun to scare the guards with. So... My name's Gonzo, musician from outer space."
"Ethan Rayne, Chaos Mage."
"I see... Well, welcome to Area 51. Don't try and get the autographs of any of the higher security prisoners... Believe me, I've asked enough times."