一名小男孩有天遇到住在他床下面的怪物，两人成为好朋友，而且男孩也发现他床下面可以通往另一个世界。A child meets the monster that lives under his bed. He even becomes one of his best friends. Soon the child discovers a whole new world of fun and games under his bed where pulling pranks on kids and other monsters is the main attraction.
