Agatha
Agatha is described as "an old Labradoodle." She is in constant pain and has been left at the veterinary clinic to be put down. After the dogs are granted human consciousness by the gods and decide to leave the clinic, she is one of three dogs that decide to stay behind. She feels that she has lived a good life, has had three litters, doesn't want to live in a world without her mistress, and sees no point in leaving with the other dogs. She doesn't realize that this means she will die so soon, however, and the next day she is euthanized by the veterinary workers who find her outside her cage and treat her cruelly. She dies wishing to see her mistress.
Apollo
Apollo is the Greek god of the sun, light, poetry, and more. In Fifteen Dogs, Apollo is notable primarily for his dispute with his brother Hermes, which leads them to make the wager that leads to the dogs' intelligence. Unlike Hermes, however, Apollo is not as concerned with human affairs and thinks humans (and all mortals) to be miserable and pitiable creatures. Late in the novel, Apollo fears that he will lose the wager on Prince's behalf, so he sends heavenly dust down to blind and deafen Prince, causing him misery.
Athena
Athena is described as a "brown, teacup Poodle." Within the pack of dogs, she is closest to Bella. Because of her small size, she has difficulty keeping up with the rest of the pack and eventually begins riding on Bella's back (since she is a much larger dog). This draws some unwanted attention from humans (i.e., it is unusual to see a small dog riding on the back of a large dog), however, so they must be somewhat secretive about it. During the day, she stays hidden while the larger dogs scavenge for food. When a number of dogs decide to conspire against them in favor of returning to their "old lives" as unintelligent dogs, however, Athena is murdered by Frick and then used as bait to kill Bella.
Atticus
Atticus is described as "an imposing Neapolitan Mastiff, with cascading jowls." He is one of the largest dogs in the pack and only physically threatened in size and power by Majnoun and Prince. He is adamant that the dogs should keep their canine instincts despite their human consciousness and rejects human language. This leads to him arranging a coup in which he takes leadership of the pack by killing and ousting any potential rivals. He is described as a "committed leader" yet also sensitive, and he begins to develop a sense of faith in a God-like ideal dog, whom he leaves offerings for. For a while, he leads the pack consisting of Max, Rosie, Frick, and Frack before being led to poisoned food by Benjy and dying. Upon his death, however, he is granted a wish by Zeus: the dog who caused his death (Benjy) shall suffer and meet a cruel end.
Bella
Bella is a Great Dane and is described as "Athena's closest pack mate." Due to her size, she is easily able to carry the smaller Athena around on her back. She enjoys Prince’s poetry and would potentially favor him over Atticus. Because of this, Atticus decides she must be killed in his plan to become pack leader. She is led to a busy street, believing her friend Athena is in danger, and—being completely devoted to Athena and anxious to help her—is hit by an oncoming car and dies.
Benjy
Benjy is described as "a resourceful and conniving Beagle." He is able to live both on his own and within the pack created by Atticus. While living with the pack, for example, he figures out that his place as a submissive dog is just as important to the hierarchy of the pack as the presence of a leader. When he sees opportunities for advancement, he tries to take them. For example, when Dougie flees, Benjy accompanies him and lives briefly with an old woman with many cats. When this grows stale for them, however, they return to the pack, where Dougie is killed. Benjy eventually poisons the rest of the dogs during his second stint with them, which leads him to Majnoun. After he tries to turn Majnoun's owners against him, however, he is ousted once more and takes up with Randy and Clare (who used to take care of Prince). Randy and Clare skip the rent on their house, however, and leave Benjy to die of poisoning when he eats rat poison in starvation.
Bobbie
Bobbie is described as "an unfortunate Duck Toller." She is killed in a frenzy along with the others as part of Atticus' conspiracy, but it is only her death that troubles Atticus. He feels that, in killing her, they did not behave in the manner of the canine because they eliminated her so unceremoniously and did not consider the implications for the pack's hierarchy.
Dougie
Dougie is a Schnauzer, described as a "friend to Benjy." He is the dog that kills the old woman's haughtiest cat and insists that he and Benjy return to the pack, only to be murdered by the conspirators immediately upon his return. Despite Benjy's self-interestedness, he is deeply troubled by Dougie's death.
Frick and Frack
Frick and Frack are Labrador Retrievers and brothers from the same litter. They are constantly paired together in the book and are part of Atticus' plan to oust Prince and Majnoun from the pack. They play a major role in the deaths of Bella and Athena. They are the youngest in the pack and easily follow Atticus as leader. Both are annoyed by Prince's poetry and are easily worked up into the frenzy of pack mentality. They eventually die alongside Atticus and Max after being poisoned.
Hermes
Hermes is the Greek messenger god, and he is the god of travel, thieves, language, and sleep. He is also the psychopomp—that is, the god that escorts souls to the afterlife. He is more concerned with the human spirit and with mortality than his brother Apollo, and he often intervenes on the dogs' behalves to help ensure that his side of the wager ends up victorious. It is he who gifts Majnoun the gift of human understanding and gifts Prince the ability to escape the conspirators' purging. He is also the god who takes Majnoun into the afterlife at the novel's end.
Lydia
Lydia is described as “tormented and nervous.” She is a cross between a Whippet (her mother) and a Weimaraner (her father). Being a nervous dog, she chooses not to join the dogs in leaving the clinic. She was left at the clinic for a minor ailment and goes home with her owners, who she now finds neglectful due to her new human consciousness. She also feels the passage of time and boredom more acutely and begins to suffer from catatonia, which leads to her owners having her euthanized.
Majnoun
Majnoun is a black Poodle. He appreciates Prince’s poetry and is attacked and left for dead by Atticus and others in the pack. He is found and nursed back to health by a human, Nira. She calls him "Lord Jim" and sometimes "Jim" until he reveals his human intelligence to her and she discovers his name is Majnoun. He lives with Nira and her spouse Miguel, developing a close relationship with Nira in which she treats him as an equal. While Benjy fuels some tension between Nira's husband Miguel and Majnoun, Majnoun eventually is able to partially find peace with Nira and Miguel. That is, until his mutual understanding with Nira confuses the Fates, and the Fates kill off Miguel and Nira while they are on vacation in an effort to keep things in order. Majnoun waits for Nira to return for a long time, before Hermes appears before him in the form of a dog, teaches him what love meant to Nira, and escorts him to the afterlife.
Max
Max is described as a “mutt who detests poetry.” He takes offense to Prince’s poetic musings and is part of Atticus’ plan to rid the pack of Prince and his supporters. He dies from being poisoned by Benjy.
Miguel
Miguel is the partner of Nira, and one of the two humans who rescues Majnoun and houses him. He does not understand Nira's closeness with Majnoun, and thinks her high opinion of Majnoun to be deranged and misguided. He envies that Nira is able to stay home while he has to go to work, and this becomes a source of friction between them towards the end of the novel. This, compounded with his displeasure at having lost Benjy (whom he preferred and thought brighter than Majnoun), leads to an argument with Nira that they resolve by planning a winery vacation. When they die away from home, however, Miguel's family shows up at the house and tries to take over ownership of Majnoun. Majnoun, however, does not allow this and flees.
Nira
Nira is the partner of Miguel, and she is one of the two humans who rescues Majnoun and houses him. Majnoun speaks to Nira, and she teaches him English throughout the novel. Eventually, when Majnoun flees Nira after a dispute over who is the "pack leader" of the household, Hermes gives Majnoun the gift of understanding all human speech. This leads to unprecedented closeness between Nira and Majnoun. They watch films together, read together, and talk about deeply personal and private things, all without Miguel knowing. This ultimately leads Nira to stop thinking of Majnoun as a dog, and a shared dream that she has with Majnoun ultimately portends that they are too close. The Fates take notice of this closeness and haphazardly kill her and Miguel to restore order to the situation.
Prince
Prince is a mutt and the first of the dogs to start using language creatively. He often recites poems that he makes up, which are appreciated by some of the dogs and detested by others. Eventually, he is ousted from the group and lives on his own in the east end of Toronto. He sometimes goes to various humans’ homes that he knows of and is there referred to as “Russell” or “Elvis," depending on the human. Before the clinic, he belonged to a boy named Kim who he has missed since being separated from him. He leads an autonomous life after leaving the pack, only crossing paths with Benjy again. He is the last of them to die, and arguably the only one to die content. Towards the end of his life, he experiences blindness and tries to teach one of his owners how to recite the poetry he has written in the pack's new language.
Ronaldinho
Ronaldinho is a mutt who decides not to leave the clinic with the rest of the pack and is sent home to his owners. However, having human consciousness changes his relationship to his loving family, and he soon finds them to be overly condescending. He ends up dying bitter and unhappy knowing that his family never knew he was intelligent and capable.
Rosie
Rosie is a German Shepherd and within the pack, she is closest to Atticus. She submits to Atticus and there are feelings of respect and deference between them. They speak the forbidden new language to each other and have a fondness for each other that goes beyond the sexual. Atticus finds this perverse, however. Eventually she dies along with Atticus after eating poisoned food.
