IHMC has been working on various legged robots for a long time. Back in 201X, my sister team worked on a running robot inspired by Ostriches (while I was on the Exoskeleton). Looks like they are mostly focusing on humanoid and Exo now. http://robots.ihmc.us/fastrunner
Here is a video from 2017 https://www.youtube.com/watch?v=q4nvpZ6WL3U&list=PLj0k5lmLZg...