My 4 year old DC has a great imagination. He has a friends called spider (who is a spider) they both live in another house round the corner from our house. He has 12 dogs and the stairs are covered in food and spiders 
When I told him that I'm not going to his house with spiders and food all over the stairs, his reply was...mummy it's ok they're only plastic 
He also said when everyone's better we need to go to Planet City and Planet Moon. I have no idea what to expect from these places but I'm sure it will be fun.
He also came into my room last year and said I don't want to sleep in my room because my toys won't stop talking, I don't know whether to be scared of that one, but we had just watched Toy Story that day.
Please tell me the stories of your brilliant little minds!