This creature is from a population evolved in 3DVCE with the gravity settings increased to 100 times the default value. At this gravity strength many, if not most, creatures die right away from a joint breaking due to the torque produced by the weight of their own limbs. But early on in a run those creatures are weeded out and the survivors reproduce and vary.

The movements almost certainly have nothing to do with the 'muscles' (servo motors) at the creature's joints, and have more to do with forces being generated by the physics engine itself to compensate for the extreme gravity (objects intersecting and repelling and such). Still, it's interesting that the population can evolve to make use of the physics engine in this way.

This creature was kindly evolved and sent in by Nathanael Plapp.