Tara Anderson, a director at 3D-printing company 3D Systems, adopted Derby from non-profit dog rescue Peace and Paws. "I kept looking at his photo and reading his story, and I cried literally every time," says Tara in the video. So she decided to do something about it and created a pair of specially fitted prosthetic legs for Derby, built in a loop configuration similar to kids’ "jumping shoes" to stop him digging them into the ground. The result is one happy dog.