Heen

Heen is a tiny, extremely old, white and brown dog that only appears in the film. He serves Madame Suliman as a covert, albeit unreliable, spy and errand runner. In the books, he appears to take the position of Percival. Waif, a little white dog, appears to be a reference to the movie character.

Sophie Hatter, who is posing as Howl's mother, is being escorted by Heen, Madame Suliman's personal errand-dog, who is dispatched from the palace. Heen is dragged up the interminable stairs to the palace by Sophie, who believes Heen is Howl Jenkins Pendragon in disguise. Sophie starts a one-sided dialogue with Heen. Heen takes her to Madame Suliman's personal entrance and brings her away from the Witch of the Waste.

Madame Suliman is seen at the end of the film peering into the orb in her staff to see him and asking him why he did not report earlier, hinting that she dispatched him to accompany Sophie to Howl's Castle to act as a spy. He shows Suliman the joyful ending scene behind him, for which Suliman brands him a "little traitor," though he doesn't appear too offended.

On any list of anime dogs, he must be included. Heen is referred to as a "little traitor" by Madame Suliman at the conclusion of the film. Although it's unclear what he did that was so awful, it's possible that he assisted mankind in some way. But Madame Suliman, the witch he was sent to guard, is not the object of his loyalty. Heen, though, continues to be utterly devoted to his youthful master, Akko.

Anime: Howl’s Moving Castle
IMDb: 8,2