Belle and Bamber

Belle and Bamber are inseparable friends. She, a 10 year old girl with a thirst for adventure; he, an imaginary blue monster. They while away their youth exploring and getting into mischief, however, when Belle's Mother tires of Bamber's influence, she pressures her to grow up and forget him. Unfortunately, he isn't planning on going anywhere. As Belle is trapped between her Mother's pressure to grow up and her increasingly homicidal imaginary friend, she has to make an impossible decision. Belle and Bamber is a dark comedy about a child afraid of growing up and the dangers of psychotic imaginary friends. - IMDb