An Automaton is a kind of robotic toy. They tend to exhibit fairly complex and anthropomorphic (human or animal like) behaviour.
They can range from Leonardo Da Vincis Robot and Vaucansons Duck to victorian showboxes (a few of which can be found in the London waxworks), where a penny would see a small and spectacular piece of mechanical theatre.
It could even be argued that more modern toys like the Tekno Robot Dog and Furby are automatons - although by replacing extremely intricate and complex mechanisms with PICs and multiple motors kind of takes some of the magic away.
There have been automatons to handwrite.
Al Jazari created a handwashing automaton.
Because of the varied and ever growing nature of their complexity - the line between automaton, robot toy and robot and beginning to blur more.