Although the creatures he and colleagues created do not currently exist in the real world, they could be created with 3D printing.
"The truth of the matter is we can print almost anything, any design," he said, noting researchers recently made an artificial ear with living cells using a 3D printer.
In creating the virtual, soft-bodied robots, the team intentionally avoided the traditional robotics' design approach, Cheney said.
"We wanted to be true to nature and introduce muscles and bones and tissues," he said.
Most of the random assortments of tissues that served as a starting point were "pretty bad," he said. "Every once in a while, you get lucky and one is slightly better. Those reproduce more ... Over time, you get some pretty amazing things."
In real life, the DNA molecule (deoxyribonucleic acid) encodes the instruction set to create a living organism; analogously, these virtual robots were created using what is known as a compositional pattern-producing network, or a network of mathematical functions, Cheney said.