As a kid, it felt as if any transforming robot other than *the* Transformers was a copycat. I have no doubt that a number of them were.
But the Transformers may not have been the first, so

**What was the first depiction of a humanoid robot able to transform into an unsuspected object?**

Answers should ideally address the differences between autonomous and (human) operated robots, and the differences between current objects and objects that are futuristic themselves, like spaceships.