It's not really a horror series, far as I can tell, but in the ten minutes of the first episode, it runs through a lot of the horror movie staples. It has all the bits and pieces, all the tropes of a horror story, but the context is just slightly off, so it all ends up falling into comedy. It's really clever.
There was an episode of Gintama (an anime) that had a radio program that did this same thing. It professed that it was going to be a bedtime story that would send you off to sleep guaranteed, but the execution was so off that it became a horror story.
It's really clever, when you think about it, requiring really exact joke construction. Gotta respect that. It could benefit from a longer time run or some rated R humor, but I think it's on Adult Swim so they might be pushing it as far as it will go already. I'm not sure at all what they allow.