You can use a screensaver as an animated desktop background in Ubuntu with XWinWrap.
Extract the file
Open the extracted folder and find the appropriate .deb file for your computer.
Install with the Ubuntu Software Center
Press Alt+F2 and run the following code in the Run Application dialogue box:
xwinwrap -ni -argb -fs -s -st -sp -nf -b — /usr/lib/xscreensaver/glmatrix -window-id WID
Replace glmatrix with the name of the screensaver you wish to use.
When you find one you like. You will need to add XWinWrap to the Startup Applications so the animated background starts when you boot your computer.
Go to System > Preferences > Startup Applications.
Choose a name and enter the code you decided on. Click add.