I recently saw an episode of a cartoon called Staines Down Drains. The episode is called Vanity Hair. In the episode, a group of people are exposed to an airborn hair growth formula.
The formula causes an eight-year old girl to grow a full beard, which she uses to dress up as Santa Claus. Also a boy grows first really hairy knuckles, and later his hair grows to Rapunzel-like extremes.
The episode is called Vanity Hair. You can see episodes of the show on this website.
www.kabillion.com . Vanity Hair isn't there, yet. But, it should be soon.