There are 3 large fields IMHO to make a robot like this: hardware, electronics and software. Same for a large range of hobby-robotics like rc planes, legged dog

There are 3 large fields IMHO to make a robot like this: hardware, electronics and software. Same for a large range of hobby-robotics like rc planes, legged dogs, etc. It's VERY difficult to be an expert in all of those, like being an expert in only one of those is already a lifetime career if you want, let alone two or even three. Oh and also, in any of them to make a robot like this would also be specialized, e.g. in software you'd need to know quite a lot about inverse kinematics, rigid body mechanics, PIDs, etc. But the nice thing of 6-legged robots and such, is that to make them at the "hobby" level you don't even need to be an expert in those fields; knowing one well and then the basics of the other two is enough to follow tutorials and build it! And it's also a lot of fun and I'd recommend anyone with a small interest to try it. I created one of those with a couple of friends, in a much rougher way (but it worked!) in a couple of days.