Yes was one of the first video I saw: as written above, it uses poses and blending from pose to pose + some compression and rotations.
What I’m working on is a more structured creature, where you start from an IK leg (3 bones), attach it to a body (a sphere that should be the pelvis) and frome there move the body and have the leg follow it on any terrain. Then add more legs, arms, bodies and so on. You can make a man, a spider, any kind of creature.