Well, a quick and not-too-thorough Google search for Yo Gabba Gabba fabric turned up nothing for me, but someone has done a quilt with appliques of the characters. Something like that might be possible, since the shapes look pretty easy.
A picture of it is on Flicker, here:
http://www.flickr.com/photos/8341340@N05/2150060757/
Edited to add: there are Yo Gabba Gabba coloring books available on Amazon, and I know everyone always says that coloring book images can be used for applique, although I've never done it.