Berk is a friendly blue creature living in a castle, home to The Thing Upstairs, the mysterious owner of the castle who never leaves his room. Berk serves his meals to him made from living creatures and does jobs for him. Also in the castle are: Boni a talking skull who is Berk's best friend: Drut Berk's pet spider, Rogg, a pink monster and Bubo, a cheeky yellow creature who often annoys Berk.