In his human form Pluto has shoulder-length, silver hair, red eyes and slit pupils, fangs, and black toenails. He is often shown nude in his human form, since he frequently changes back and forth from his human form to his demon hound form. Eventually, he wears a suit. In his demon hound form he becomes a immense and monstrous dog, with white fur.
He never speaks, and simply makes dog-like sounds, such as howling, barking, and whining noises. Even in his human form, he retains dog-like characteristics, such as continuing to run around on all fours and using his nose to find things. He can turn into his human form upon will, or unintentionally when excited.
Pluto does not seem to be overly fond of most people, but listens to Sebastian Michaelis most of the time and is notably envious when Sebastian gives his attention to a cat. He likes Innuko dog treats.
In Black ButlerEdit
When the Phantomhive household goes to the village of Houndsworth, they initially believe the legend of the Demon Hound to be a farce created by Henry Barrymore, but when he is dragged from the cell where he was being kept and is found dead, they investigate further.
Finnian, Baldroy, Mey-Rin, and Tanaka initially discover a strange, nude man, and before they can investigate him further, they are distracted by the townspeople. When they turn around, they see a large Demon Hound, but decide to follow him further when they notice he is carrying part of Angela's clothing. However, it turns out that he was just her pet, but had killed Henry because of his abuse of the Demon Hound legend. Angela asks if they will take him in so he can behave better, and Ciel Phantomhive agrees, knowing how much Sebastian despises dogs.
Shard of HopeEdit
He aids Ciel, Grell Sutcliff, and Sebastian in finding Elizabeth Midford by unsealing the door to the tower she is being held in. After their fight with Drossel Keinz he is seen calmly laying at Drossel's master's feet, much to Ciel's and Sebastian's surprise. It is later shown that the reason for this is because the puppet manipulating Drossel was controlled by Angela.
Conspiracy and RevengEdit
Pluto is seen when Mey-Rin, Baldroy, and Finnian recall their pasts and how they were recruited. He is seen helping Finnian with his gardenwork, though he creates more problems by burning all the trees. Later, he uses his fire breath to defend Phantomhive Manor.
When Ash goes on the rampage, he uses Pluto's demon hound abilities to set most of London on fire. As he goes out of control and cannot be stopped with mere anesthetic, Ciel orders his servants to kill Pluto. Mey-Rin, Finnian, and Baldroy sadly agree, and using their various skills, are able to take him out, injuring themselves in the process.
In the end Sebastian promises Ciel that he would "gather Pluto's bones" later, indicating that Pluto had been killed.
Story of Joining Sora's TeamEdit
As the Sora entered Ciel's world, with Goofy, Juvia, Scanty, Ness, Sofia, Riku, and Barrel they began to start their search for the Keyhole at the Phantomhive Manor. When the group knocked on the door, Pluto stood behind and jumped on Sora with happiness due to the light in his heart. As Ciel and Sebastian answered, they were both surprised to see an unusual group, and as they saw Pluto on top of Sora repeatingly licking his face, Ciel invited them in to let them explain there business in England. When Ciel and Sebastian discussed whether or not they should help them find the Keyhole, Ciel thought they were talking nonsense about Heartless, Nobodies, Princesses of Heart, and Organization XIII. But as soon when Sebastian escorted them out, they all engaged in battle as Pluto warned the group about the Heartless, Subspacers, and Zelnemies. Soon after the fight, Ciel and Sebastian decide to assist them on their mission. Once they teamed up, Scanty pointed out there was a shadowy figure behind the trees, as it was Grell Sutcliff. Once Grell wanted to help, he also stated that he doesn't want to work for Master Xehanort if he takes over their world. Soon as they agreed to work together, Tanaka Mey-Rin, Finnian, Lau, Baldroy, Snake, and Ran-Mao suddenly appeared as they were eavesdropping and overhearing their conversation they joined in on the "fun" also. When they all separated in teams of 3, Barrel, who was with Lau and Tanaka, messaged the others that the Keyhole was located in Elizabeth Midford's manor where the Heartless were arriving at. Soon as everyone met up, they wer all surprised it was the Undertaker and Vanitas that were standing together holding Elizabeth and Paula captive. Soon as everyone engaged in battle, the showdown lasted about 37 sec. After the showdown, Ciel and and Sebastian decided to join Sora on his journey after Sora and Riku sealed the Keyhole with their Keyblades. And even everyone else joined to save their world and assist the team, including Grell. Soon Pluto was givin to Sora by Ciel as a pet and became the teams main member.