TV-Series
Description
Pluto, also known by the nickname Plu-Plu, is a demon hound who appears in the first season of the Black Butler anime. He is first encountered in the village of Houndsworth, where the local people regard him as a terrifying devil dog that has been menacing the town. Before coming to the Phantomhive household, he was kept by Angela Blanc, a maid who is later revealed to be the angel Ash. When Ciel Phantomhive and Sebastian Michaelis investigate the village, Sebastian manages to subdue and tame Pluto, after which the creature is brought to the Phantomhive estate and accepted as part of the household.

In his demon hound form, Pluto is an immense and monstrous dog with white or gray fur, red eyes, and black toenails, features that mark him as a demonic being. He can also adopt a human form, appearing as a tall young man with shoulder-length silver hair, red eyes with slit pupils, and small fangs. In both forms, he is unable to speak and communicates only through dog-like sounds such as barking, howling, and whining. Even in his human shape, he keeps canine behavior, such as running on all fours, using his nose to track things, and showing affection without embarrassment by licking people or remaining naked.

Pluto's personality is playful, affectionate, and instinct-driven rather than malicious. He becomes deeply devoted to Sebastian, the one who tamed him, and he obeys only Sebastian's orders, despite Sebastian's dislike of dogs. He also displays jealousy when Sebastian gives more attention to a cat than to him. Among the Phantomhive servants, he is especially close to Finnian, who is the only one strong enough to walk him.

Pluto possesses several notable abilities. He can breathe fire, pass through barriers that would stop ordinary beings, and shift between his canine and human forms, sometimes changing unintentionally when excited. He also has immense physical strength, which makes him a powerful guardian when controlled but a dangerous threat when he loses control.

Pluto's role in the story grows more significant as the first season progresses. There are early hints that he has a connection to the organization responsible for the deaths of Ciel's parents, as he is shown resting by the feet of one of its members and licking his hand. His prior bond with Angela also ties him to the angel's plans. Near the end of the season, Ash uses Pluto to set fire to the Phantomhive mansion and later to burn London. Pluto loses himself completely during this rampage and becomes impossible for even Sebastian to restrain. Ciel, concluding that Pluto is no longer the creature they once knew, orders his servants Bard, Mey-Rin, and Finnian to kill him. Pluto's death is not shown directly; only gunshots and his pained howls are heard. In the final episode, Sebastian confirms that Pluto was killed and offers to collect his bones for Ciel.

Pluto's development follows a tragic arc, moving from a feared monster, to a tamed companion and beloved member of the household, and finally to a manipulated weapon who is destroyed by the very family that had come to care for him. He appears only in the anime adaptation and does not exist in the original manga storyline.
Cast