Drinking Bird. A rather dumb looking 6" bird with a felt covered head and has plastic feet. Worse, he cannot get his fill of water. You buy the drinks.
Fluid inside condenses from the evaporative cooling of the water off the bird's beak, making it top heavy and dunking it back into the water. The condensate rejoins the liquid pool in the bird's bulb, and he tips up again.
WARNING! The fluid and dye inside the bird can permanently stain, and the bird's glass body can easily be broken. Children are fascinated by the bobbing bird, and the educational possibilities are great. But they should watch it, not fondle it!!