The Charlie the Unicorn "Hot Topic" Video was a video created by FilmCow to advertise the Charlie the Unicorn merch available from Hot Topic.
The video opens with text reading "CHARLIE THE UNICORN ...AND THE TOMB OF HORRORS". It then cuts to Blue standing on a pillar over lava asking Charlie where he is, whilst Pink falls into the lava. Charlie says that he is in front of a chamber, and Blue asks whether it is the chamber of madness or death. Charlie asks if it matters and Blue says that he must tell him because he's on fire. The pillar Blue is standing on begins to sink into the lava as they tell Charlie not to talk to the Weasel.
Suddenly, a weasel appears in front of Charlie and begins to talk to him, but Pink and Blue appear and shoot lasers out of their eyes at it. They ask if Charlie spoke to it, and Charlie says he didn't, however, Blue reveals that they are in fact the Weasel and Pink points out that they're all naked.