Otto Is a Rhino(1983)

Overview:

The boy Topper is bored. He finds a pencil that proves to have magical powers. Draw a rhino, and right away, you have a real rhino for a companion. A little heavy perhaps, when you live on the second floor. No matter, it's a modern fairy-tale of the baroque, and everything goes. Based on kiddie entertainment by Ole Lund Kirkegaard, but as was the case with the book, the fun is to be enjoyed by one and all.