I have four cats and they lose toys all the time but when a Christmas mousey goes missing, it's time to pull out the flashlight for some spelunking. 

This was a Daz3D render. I created 8 layers total to get the full effect. Then did some post production work to sharpen it up and bring out the 'life' in it.

Essentially, it was rendered once as a complete image, once without the characters and DOF on, once with just the figures in a position to get some realistic reflections, once with just lights, and once with just toys. This allowed me to do a bunch of selections in Photoshop easier, without the struggle of having to pick characters out of the background.

Render time: 12 hours (for all parts)

Post Production time: 3 hours.