Bilbo Baggins is the main character from Tolkien’s earlier book The Hobbit, also set in Middle-earth. In it, Bilbo joins a group of dwarves on an adventure to steal a hoard of treasure from the dragon Smaug, and regain the Lonely Mountain from him. Their quest sees them pitted against trolls, goblins, giant spiders and wood elves. Underneath the Misty Mountains, Bilbo is separated from the others and stumbles across a magical ring. He then engages in a battle of riddles with the ring’s current owner, the creature Gollum, eventually using the ring to become invisible and escape. Finally, the dragon is killed and the treasure recovered. Bilbo returns to the Shire a more adventurous, less stuffy, and much richer hobbit.
The hobbits of the Shire are a very conservative, respectable folk, disapproving of excitement and adventures in general. They regard Bilbo as their somewhat baffling and rather eccentric neighbour.