This was what Marcus just told me a few minutes ago as he played with playdoh. He has been making up stories about monsters in various parts of the house recently and how they are coming after him so he can't go to bed alone. He is very insistent at times of why he needs to come out to the living room to play as there is a monster under his bed.
(As I type this post, he stopped playing his playdoh and sat next to me to read. Funnily, he commented "yeah mummy, there is a monster under my bed! See!!")