In deference to the season, it's all about Zombies.
From the update:
The Grabby House is a paired spawning point, and is much like other spawning points. There are two things to draw your attention to though.
First, it has 4 hearts. All paired spawning points now have 4 hearts. This gives them a little more staying power, since they both take wounds when spawning.
Second, Grabby Hands grants every monster with sapphire affinity (blue) within 2 squares the Grabby ability. What is Grabby? Well it is the signature zombie ability, which makes it so that no enemy model can move while it is adjacent to a model with Grabby. That's right! Once a zombie grabs you, the Hero needs to chop it to bits before they can get away. Dirty!