The drinking bird is a classic toy. I remember my dad bringing one home when I was a child so that's at least 50 years ago. A Chinese drinking bird toy dating back to 1910s-1930s named insatiable birdie is described in Yakov Perelman's Physics for Entertainment. It is a heat engine that works from the temperature difference between the bottom bulb, which is around ambient temperature, and the head, which is kept a few degrees cooler by evapourating water. The head is covered in a felt-like material which is kept wet by periodic dipping in a glass of water.
An excellent description of how it works can be seen on Wikipedia HERE
The toy works reliably, as long as the water is kept topped up within reach of the birds beak