It at one point wanted to absorb all human information. All things that humans can feel. It is grabbing humans and extracting one emotion from each (the process kills the subject human) and trying to accumulate them all. It is trying to understand every human emotion for unknown reasons, and it does this by grabbing a person, hooking up its tendrils inside their nervous system, and then inducing whatever sensation corresponds to the emotion it's trying to understand. When it understands, the person dies and it moves on to discovering a new emotion.