Ghengis is a very classy walker created by Rodney Brooks of i Robot.
It has six legs, and uses Subsumption Architecture.
It has an array of heat sensors, and is built up with behavioural layers from a basic instruction top stand, through to walking(lifting a foot, and following with an involuntary step reflew), through to a complex hunt and prowl behaviour.
Ghengis sensing behavioru is based on movement. When it senses movement, it will turn towards it, and walk towards the stimulus.

Time to build your own robot! Using a Raspberry Pi with parts and some time, you can use my book to learn how to make and program a robot with automatic behaviours.