I read the IEEE article, very cool!

This reminds me of robots from long ago. The article states that this isn't the first legged robot, and many of us have seen the legged ones from Boston Dynamic. This isn't the first animal robot either.

In the late 1940s a man in the UK named Dr Grey Walter made a pair of tortoise robots that could sense the world and respond in a crude way of course. These robots moved on wheels and had an early type of photocell to "look" at the world. It also had sensors in it's "shell" that could detect when it bumped into something.

I first read about this in an old Scientific American magazine.
https://www.scientificamerican.com/article/an-imitation-of-life/

Dr Walter also wrote a book about his tortoises called The Living Brain.
https://www.amazon.com/Living-Brain-W-Grey-Walter/dp/0393001539

You can read more in this wikipedia article:
https://en.wikipedia.org/wiki/William_Grey_Walter

Also, there is video of Walter and his bots! Check it out!