Zottelkralle is a very special earth monster! He can't stand the typical earth monster smell, prefers to eat human food and soap, and loves piano music above all. It's no wonder he wants to nest in Kalli's house, because here he finds everything Zottelkralle dreams of. Kalli thinks the monster is wonderful, even though Zottelkralle is greedy, lazy, chaotic, and extremely unfriendly. But one day, Zottelkralle goes too far: he turns the whole house into a dump, and Kalli's mother puts him out on the street. How can Kalli convince his parents that Zottelkralle is the best roommate one could imagine?.