In case you don't want to watch the first teaser trailer for Amnesia: A Machine for Pigs, let me summarise it for you: Pretty, pretty, pretty, pretty, oh god what is that? What the hell is that?!
There's a terrifying monster pig creature out there, and the truffles he's rooting for are your soul. If you were wondering how Dear Esther developer TheChineseRoom was going to make the sequel to Frictional Games' Amnesia: The Dark Descent even scarier, this should partially answer your question.
Frictional originally planned on releasing this teaser once the latest Humble Indie Bundle his a certain number, hoping to use it as incentive for purchase. By the time the trailer was ready sales had already surpassed any milestone they were going to set, so here we are.