The original WATCHGOOZ3, described in my book "The LEGO MINDSTORMS EV3 Laboratory", can be built using the LEGO MINDSTORMS EV3 retail set 31313.
This version can be built using the LEGO MINDSTORMS Education EV3 Core set 45544.
This biped robot can balance, walk and avoid obstacles.
It can be even programmed without a computer.