>>22782356I would make it so the legs on one side don't move in the same manner as the other side's set of legs. For example, look at the animation for the back frames of Lairon's overworld. The front legs move in the opposite direction of the back legs (like you have it doing now in Anvelid's animation), but each side's set of legs move in the opposite direction of the other side.
So if the left side's front leg is moving forward and the back leg is moving back, then the right side's front leg would be moving back while the back leg would be moving forward. Then on the second frame it'd be reversed.