Continuity mistake: The first time Otis is in the barn at night he carries a glass of milk in his hand. However, when Daisy sees him, the glass of milk disappears from his hand.
Continuity mistake: In the scene where Otis is sitting the farmer against the tree, after the mule kicks the farmer in the head, Otis places a copy of "Charlotte's Web" in the farmer's lap. When you see Otis positioning the book, the book is open towards Otis. When you see the farmer under the tree, the book is open towards the farmer.
Continuity mistake: When the farmer buries Ben, the dirt on the grave is flat with the surrounding grass. When Otis visits the grave later, the dirt appears as a mound.
Answer: The character is named Freddy the ferret.