The Grouch
Back in the 1990s there was a System Extension called "The Grouch." The extension would run an annimated Oscar the Grouch and sound byte whenever the system trash would be empty.
This became a cool novelty that kids would put stuff in the trash just to see the animation and sound. This is from the version 2.0 Read Me file:
The Extension version of "The Grouch" plays an animation every time "Empty Trash" is selected from the Finder's "Special" menu. This version must be placed into your System Folder (or Extensions folder under System 7) and you must "Restart" your system for it to work.
The Application version was created after several parents informed me that their children liked "The Grouch" so much they threw out all of the files on their hard disks. This version is child-proof as far as I can tell since it is completely self- contained. It does not modify the Finder and draws the animation in a window instead of on the desktop. It does not require the Extension to be present.
Sadly the developer, Eric Shapiro never ported over to Mac OS X.
Audio Clip
Here's a copy of the sound that people would hear when the animation was run. This is a combination of the two sound bites: