The art of making mechanical creatures that look like animals is called animatronics. If you create a robotic cat, you've mastered the technique of animatronics.
Before computer animation became versatile and sophisticated, many movies used animatronics to create the illusion that people were interacting with dinosaurs or imaginary creatures. Animals created using animatronics are robotic, but they appear fairly realistic. Walt Disney was the first film director to use animatronics, in the 1960s,though he originally called the technique Audio-Animatronics.