This robot not only flies, it compresses to enter small spaces.

The FSTAR hybrid (flying sprawl-tuned autonomous robot) is not only a robot capable of flying like a quadricopter, but of driving in difficult terrain and transforming itself to access reduced spaces, using the same engines, as you can see in the following video.

FSTAR will be presented at the 2019 International Conference on Robotics and Automation in Montreal on 21 May.

FSTAR
Developed at Ben-Gurion University in the Negev by Mechanical Engineering professor David Zarrouk and his graduate student, Nir Meiri, the FSTAR adjusts its width to crawl or run on flat surfaces, climb large obstacles and climb very separate walls, or go through a tunnel, pipe or narrow spaces.

He can also run on the ground at speeds of up to 2.6 meters per second, as Zarrouk explains:

We plan to develop larger and smaller versions to expand this family of extensive robots for different applications, as well as algorithms that will help exploit the speed and transport cost of these flying robots/drivers.