It's a flying robot - it's an amphibious robot - it's an explorer of alien worlds. It's NASA's Shapeshifter robot.
In a dusty robotics yard at NASA's Jet Propulsion Laboratory in Pasadena, California, the Shapeshifter team is testing a 3D-printed prototype of this unusual explorer. A contraption that looks like a drone encased in an elongated hamster wheel rolls across the yard, then splits in half. Once separated, the two halves rise on small propellers, effectively becoming flying drones for aerial exploration. These 3D-printed parts are only the beginning; the team imagines a series of up to 12 robots that could transform into a swimming probe or a team of cave explorers.
JPL Principal Investigator Ali Agha envisions Shapeshifter as a mission to Saturn's moon Titan, the only other world in the solar system known to have liquid in the form of methane lakes, rivers and seas on its surface...
Agha and his Shapeshifter co-investigators, who include researchers from Stanford and Cornell universities, came up with the concept of a self-assembling robot made of smaller robots called "cobots." The cobots, each housing a small propeller, would be able to move independent of one another to fly along cliffsides of scientific interest. They could also go spelunking, forming a daisy chain to maintain contact with the surface. Or they could transform into a sphere to roll on flat surfaces and conserve energy.
In his 1920 classic short story The Metal Monster, Abraham Merritt described a multipart robot that functioned as a single entity:
Faster the cubes moved; faster the circle revolved; the pyramids raised themselves, stood bolt upright on their square bases; the six rolling spheres touched them, joined the spinning, and with sleight-of-hand suddenness the ring drew together; its units coalesced, cubes and pyramids and globes threading with a curious suggestion of ferment.
With the same startling abruptness there stood erect, where but a moment before they had seethed, a little figure, grotesque; a weirdly humorous, a vaguely terrifying foot-high shape, squared and angled and pointed and ANIMATE—as though a child should build from nursery blocks a fantastic shape which abruptly is filled with throbbing life.
(Read more about living metal cubes)
I'd also mention Philip K. Dick's M from his 1957 short story The Unreconstructed M.