Menzi Muck A91 with a grapple
The walking excavator’s main feature is the ability to move in a crab- or spider-like fashion and hence overcome any terrain obstacle. The undercarriage design varies widely from model to model and between specialized roles. The number of legs or wheels can also vary from three (Menzi Muck 5000T2) to four. The leg design can also vary from fixed to telescoping. Most walking excavators now have rotating or powered wheels, allowing them to roll or drive depending on the need.
Watched one of those (they called it a spider) go near vertical installing a power pole in the back country. crazy articulation for something so big.