It's a well-known fact that everything is better with puppies. Your renders are no different. Fortunately, the website Viz-people is here to help, offering a free set of 6 cut-out cat and dog .PNGs. Pets aren't the only cut-outs on offer (just the cutest—sorry, cut-out kids); in addition, Viz-people has a whole raft of free stuff for 3D modeling and rendering, including 2D cutouts of people, textures, and skies, and 3D models of cars, trees, chairs and more.
Get the cats and dogs download here, check out all of Viz-people's free downloads here, or for the pros, explore the rest of the site to see their full set of paid downloads.