Hilda and the Midnight Giant (2)

Hilda is a little girl with the uncanny ability to befriend even the most peculiar of house guests. But when an army of little creatures bombard her living room with stones and eviction notices, she has to think twice before making the acquaintance of these diminutive creatures. After sunset, even stranger things start happening. Who is this giant who only appears at midnight, and why is Hilda the only person who can see him?