Who is Mr. Saturn?  We all are Mr. Saturn!  Zoom! Boing! Ding! 
 
Something I've had sitting in my GMod folder that many people have wanted to download, I fixed it up a bit and released it.  Download link at the bottom!  Extract to  garrysmod/garrysmod/addons

 

I don't mean to be a buzzkill but...

One Youtube video answered with another
 
This is the real Mr. Saturn:
 

All it needs is the Saturn Valley music when he spawns. That'd be great.

This is awesome! Will download.
Edit: Playing with this mod and a friend right now. Awesome fun. Great job Aska.