Sometimes products just take off, and really there's no reason for it. This is a drinking bird, that was popular in the early 70s. Basically you would fill a shot glass with water (what home didn't have a shotglass back then??? We had several), and you would push his head down into the glass, and he would continually lower his head into the 'liquid' and raise it up again, like he was drinking. He would drink indefinitely. Up and down, up and down, up and down. He could drink anyone under the table - definitely an invention of the cocktail generation.
I wanted one so bad, but was disappointed when I got it (don't ask me what I was expecting). I don't know what happened to it, but it never mattered because it was a rather dull thing to watch, which is why most you find on ebay are unused. To this day you can't even give them away on ebay.
Click on the photo for a larger view.