Bob

Bob is a spirit of intellect bound to a human skull. He acts as Dresden's assistant and living encyclopedia of magic. He first appears in Storm Front.

Description
Bob has been assisting wizards since the dark ages; innately knowledgeable about the rules and status of the supernatural realm, he has therefore gathered extensive information and experience in applied magic, which he does not forget, unless he intentionally chooses to do so. He is, however, incapable to make most moral distinctions between good and evil.

In Ghost Story, Bob's self-representation is of an ordinary looking young man, moderately tall, slender, with decent shoulders, dressed like James Dean in a biker jacket, with an embroidered skull over the heart, and a white shirt which appeared forced on him.

Queen Mab shows a strong interest in Bob, considering his knowldege of how to kill immortals a strong risk to her and her court.

Personality
Under Harry Dresden, Bob is benign and helpful, if smart-mouthed; however, he is also a sexual pervert, insiting that Dresden buys him romance novels as 'payment', and every time he is let out of his skull, he causes trouble, usually sexual in nature.

In Storm Front, Bob is given a 24-hour pass; at the end of the book, Dresden "looked the other way" on a party that lasted for an entire day.

In Fool Moon, Harry Dresden chides him for invading a party and inciting an orgy after having earned a day out, to which Bob replies by saying "I didn't do anything to anyone that a keg wouldn't have done".

Every time Molly Carpenter comes to Dresden's apartment, Bob relentlessly pesters him to let him talk to her. It's likely that he is influenced by his owner's personality - if this is the case, Bob's tendency to be smartmouthed is likely a direct consquence of his cohabitation with Harry.

Under Waldo Butters, he acts a lot like he used to with Dresden, due to Butters knowing Harry, basing his personality off that first impression.

Skull interior
It is a penthouse very much like James Bond apartment. There is black marble, mahogony, a huge fireplace, and matching hand-carved hardwood furniture as well: couches, recliners, two chaises, covered in fabric like raw silk embroidered with sigils in gold and silver. There is a table with a huge spread including a turkey, fruits, vegetables, and multiple side-dishes. A curtain hides a huge TV, a stereo system, and multiple video game units.

Biography
Bob was bound to the skull by Etienne the Enchanter in France, at the time of the medieval Inquisition.

A few centuries later he was owned by Heinrich Kemmler, pursuing dark interests for close to forty years. After Kemmler's death, the White Council Wardens thought Bob destroyed, but he was in fact taken by Warden Justin DuMorne.

DuMorne later left the wardens, secretly keeping Bob for himself. It was in this time that Bob was instructed (or possibly chose) to forget about his time with Kemmler and the work he did, thus destroying many things and locking away what couldn't be destroyed. Because Bob is a spirit of intellect, and is made of knowledge, losing this information would amount to a human losing a limb, or worse. After DuMorne was killed, Harry Dresden picked up Bob's skull.

Bob's skull was picked up by Harry Dresden after the death of Justin DuMorne, and it was with him that he was called "Bob" by Dresden.

Bob is able to lend Dresden access to his vast magical experience, often providing vital information about magical objects or rituals or difficult problems. As a form of payment, Bob often demands trashy romance novels; Dresden theorizes that being a creature of intellect himself, Bob somehow identifies with characters that exist only in the mind living therefore vicariously through their actions in novels. Dresden notes that it was entirely possible that Bob merely looked at them the same way some men look at blow-up dolls. It also seems to help Bob to stave off his more impulsive urges.

In Ghost Story, Bob reappears again, under the control of Butters. The evil piece of himself that he split off from is assisting the Corpsetaker on attacking Mort's home. It is revealed that he looks attractive in spirit form and can literally curbstomp any ghost, wraith, or spirit other than his evil self and Corpsetaker. The inside of his skull is similar to a mansion.

Storm Front
In Storm Front, he helps Harry Dresden make an escape potion and a love potion, the latter at his insistence. Later, when Susan Rodriguez accidentally drinks the wrong potion, they're trapped in the lab's circle and the potion kicks in. Dresden lets Bob out so he can throw him the escape potion in exchange for twenty-four hour leave. Bob returned after a wild party at the University of Chicago.

Fool Moon
In Fool Moon, Bob helps again Dresden to brew two potions, and informs him about therianthropy, lupine theriomorphs, werewolves, lycanthropes, loup-garous, shapeshifting, etc. Dresden bribes him with new romance novels in exchange for him engaging on an information hunt on werewolves in Chicago.

Grave Peril
In Grave Peril,

Summer Knight
In Summer Knight, Bob and Dresden discuss the hierarchy of the Sidhe Courts. Bob tells Harry that Ronald Reuel was the Summer Knight.

Death Masks
In Death Masks, Dresden gets out his copy of the Unseelie Accords to look up the Code Duello in preparation for his duel with Paolo Ortega but can't make out the hight-toned language. Bob gives him the CliffNotes version. They also talk about the plague curse that got that corpse in the morgue and the Eye of Thoth. Dresden shows him the drawing of the sigil and Bob freaks, tells Dresden to throw it out or burn it. He says they're worse than just Fallen: assissins, poisoners, sorcerers, warriors, the coins make them nearly immortal. Bob can't track down the Shroud of Turin, it's an object of faith and not his jurisdiction and suggests he talk to Ulsharavas. Dresden sends him out to find what he can about Paolo Ortega and to swing by Marcone's estate.

Later, Bob returns from his info-hunt reporting reports that Ortega is at the Rothchild Hotel with six vampires and a dozen mortals. He's badly hurt by Marcone's estate's wards, which were made by Gard, Marcone's newest security person.

"Publicity and Advertising"
In "Publicity and Advertising", he and Harry Dresden argue on how better to write an announcement on the Yellow Pages.

Blood Rites
In Blood Rites, Dresden asks Bob to ride Mister in an attempt of locating Black Court vampire Mavra and her scourge. The next morning, Harry is woken up by Mister, inhabited by Bob, walking over his face. Upon his return, Bob admits going to strip joints rather than sticking to his mission; Dresden is forced to threaten to break Bob's skull with a hammer until he re-inhabits Mister and goes out again.

Later, Bob returns and reports. Mavra is in a homeless shelter near Cabrini Green. They most likely came from Undertown. Bob draws a map of the shelter and its lower levels. There are people locked on a closet, six Renfields each with a darkhound and the staff are changed into rough thralls. Bob teaches Dresden about Renfields and that the White Court had Stoker publish his book to tell people about them. Black Court vampires use mind control magic to recruit Renfields. Bob says that even the Original Merlin could not undo a Renfield. Justin DuMorne had done a lot of research on the subject so he's sure of his facts.

Dead Beat
In Dead Beat, when Harry Dresden asks Bob to remember what he can concerning Heinrich Kemmler, Bob refused to answer unless Harry let him out for the duration of the conversation. Once out, he warned Harry about the dangers of him accessing these memories. Once ordered to access said memories, he tricked Harry into being tainted with a hint of necromancy, and almost killed Harry before being ordered back into his skull.

Later, he was stolen by Cowl and Kumori  and assumed an alternate personality. It is currently unknown whether he was faking this personality, or if he is forced to become attuned to his current holder. Once put down by Cowl, Harry reminded Bob about how he had Named him, as previous owners had simply called him "spirit", which supposedly freed Bob to help Harry. When he helped Harry, he took over Sue the T-Rex and compared that or any other zombie to a choice between steak or a hot dog.

Proven Guilty
In Proven Guilty,

White Night
In White Night,

Backup
In Backup, Thomas Raith asks him to explain how best to disarm the trap the Stygian Sisterhood has set for Harry Dresden without violating the guiding principles of the Oblivion War.

Small Favor
In Small Favor, Bob assists Harry Dresden in identifying the fae assassins as the Gruffs. They also discuss the nature of Soulfire, contrasting it with Hellfire.

Dresden theorizes that the characters in the novels Bob reads may somehow be "real" to him.

Turn Coat
In Turn Coat,

Changes
In Changes, Bob looks a photos of a Red Court shipment. He says that they're ritual objects of dark and dangerous magic, which is obvious from angles and the imbalance, they are meant to be destructive. They are meant for Human Sacrifice. The slaughter of an innocent.

Harry Dresden takes Bob into the Nevernever with him escaping the FBI Barry Tilly and Rudolph. While there they are confronted by giant centipedes. Harry is forced to go back and be arrested. So, he stashes Bob, the Swords of the Cross and bag in a hole. Mister was sprawled across Bob's shelf using his paperbacks a a pillow. Dresden rub's Mister's ears and promises himself to get Bob back soon, for now, he was safely hidden in a hole in the Nevernever. TheLeanansidhe later returns Dresden's bag with Bob in it. In Chichén Itzá, Dresden takes Bob out of he bag, shows him the set-up for the ritual Bloodline curse, Bob tells him what he's dealing with. Bob creates a shield that blocks the power of the Red King, freeing Harry, who then has him follow Murphy to protect her, to his utter delight. At the end, Bob floated out of the P-90 and back into his Skull complaining that it was too close to dawn that Harry got him out.

Ghost Story
In Ghost Story, Waldo Butters and Bob save Harry Dresden's ghost from a pack of lemurs eating him. Bob kills the Lemurs then returns Dresden's essence to him. Dresden rides along with Bob inside the skull. Bob and Harry talk over Harry's situation, and acts as a sounding board for who may have killed Harry. Bob suggest that Harry is the subject of a shell game involving Mab and Uriel. And, He Who Walks Behind was Justin DuMorne's mentor, not the other way around—that Dresden was being pushed into becoming a weapon. Plus Dresden is running around in his Soul without his spirit. (His theory is that the: "Spirit is the seed and the soul is the earth it grows in.") If something happens to him here, it's for keeps. Dresden had a choice, but didn't read the fine print. Bob fought with Evil Bob in the Nevernever allowing Harry and his ghost-troops to escape and enter the Big Hoods' hideout: Corpsetaker's stronghold.

Cold Days
In Cold Days, Harry Dresden breaks into Waldo Butters' apartment to steal Bob; Andi attacks him. Dresden extricates himself with the idea that stealing the skull, rather than borrowing it, is a perfect cover against competitors. Bob admits that Mab wants to destroy it for his knowledge of how to kill immortal beings, making Dresden promise to build it a new house in exchange of that knowledge. Bob also tells Dresden about Conjunctions in time and that Halloween is the one on which immortals are mortal and vulnerable; they are refueling on energy and adding power to their Mantle.

On Demonreach, Bob said the spells on the rocks of the tower were complex and impossible but someone didn't care. Harry and Bob followed the Demonreach Entity down into a deep well on the island where he showed them the Naagloshii and the Dark Gods imprisoned there. Dresden is now the Warden of the prison. Bob played a movie for Dresden showing The Original Merlin creating the prison in various times but all at the same time, building an immortal jail in four dimensions. The problem: a whole lot of energy hits the containment spell, it will unravel, releasing the nightmare prisoners.

Murphy got Harry Dresden to agree to return Bob to Waldo Butters because he's too valuable to let fall into the wrong hands.

Skin Game
In Skin Game,

Concept and creation
Jim Butcher had this to say about his inspiration for writing Bob:

"Bob started off as an inside joke between my writing teacher, Debbie Chester, and myself. I needed a device to get the rules of magic across to my readers, so that they would have a point of reference for the laws of my story world. I talked with Debbie about maybe designing a character whose fundamental function was to have conversations with Harry about the nature of magic, so that the readers could all understand what was going on. “Sounds fine,” says Debbie. “But whatever you do, don't create some kind of talking head.” In story craft terms, a talking head refers to a character whose purpose in life is to dispense information. Talking heads will wander onto the page, blurt out exposition without bothering to display much in the way of character or motivation, and promptly exit. So when I designed Bob, complete with his little obsessions and quirks, I decided to make him a literal talking head, while avoiding the traits that add up to a story-craft talking head."

The idea of the skull itself was inspired by the Scooby Doo splash screen.

Quotes
Harry Dresden: "Come on, lazybones."

Bob: "It isn't enough that I have to wake up. I have to wake up to bad puns."

Bob: "What's up, boss?"

Harry: "Evil's afoot."

Bob: "Well, sure, because it refuses to learn the metric system. Otherwise it'd be up to a meter by now."

Word of Butcher
Jim Butcher has stated that that Bob takes on some of the personality of his "master", explaining that he is such a smart aleck and into girls because Dresden picked him up when he was just 16.