This is a 7 minute short film by Chris Cunningham, about a shape-shifting, mutant child named Johnny, who is kept in a basement with only his dog and his imagination for company.
It has also been suggested that Johnny is merely a hallucinating drug addict, because at one point in the film you can see him snort a line of white powder.
However, the original concept was for a video of a raver morphing as he danced, which eventually evolved into the concept of a music video/short film about a mutant child keeping himself occupied.
While incredibly disturbing, it's definitely worth a few watches. Once the initial shock of the images wears off, a vastly creative video shows itself through all the creepiness.
Filmed almost entirely in night-vision, the film has a grainy, documentary feel to it, which is why upon first watching it, some people concluded it was actual footage of a mutant.
With original music by Aphex Twin (inserted into the film as a remix done by the director himself) the latter part of the video does more resemble a music video than a documentary, and you'll almost certainly find yourself watching the last 2 or 3 minutes again.
In all, disturbing and unforgettable. Not for the easily scared or sensitive.