The British folklore they exist mostly in the north of England and others of its kind their role is to help humans. They partake in the everyday task as a form of labour and are given sometimes the job of guarding a treasure. Dobbie is not known for their wisdom and they make mistakes or are easily confused. In parts of West Yorkshire, the name Dobby is applied to an evil fairly who leaps on to the backs of unsuspecting travellers on horseback and suffocates them. Dobby is also known as the creature from J.K Rowling Harry Potter series of books. Dobby in the Harry Potter stories takes on the role of helping the wizard Harry Potter in the books with some events like in the books Chamber of Secrets, Goblet of Fire, Order of the Phoenix and Deathly Hallows. In the movies, some parts that Dobby played in the books were replaced by Neville Longbottom like in the movies Order of the Phoenix where Neville find the Room of Requirement in the movie. But in the book, it is Dobby that finds the door for Harry Potter to teach people spells for that are forbidding to be taught in class and are taught outside class in secret as a form of defending themselves from evil.
John and Caitlin Matthews, The Element Encyclopaedia of Magical Creatures, 2013, Dobie/Dobby , p 136