Kiba is a canon character of the anime Wolf's Rain. He is a large, pure-white wolf who can communicate telepathically and use a human illusion for disguise, although he possesses large fangs and it is appearance-only; in the opera house's cellars, Erik noticed that Kiba's footsteps were quadrupedal despite his human appearance. If he cannot find food, he can restore his energy by basking in the moonlight. It will help for quite a while--wolves with extreme willpower can last up to a month with only moonlight to sustain them--but it is no substitute for actual nourishment and eventually he will have to eat something.
As his author Jamie describes, Kiba is "the polar opposite of cuddly and nice." The best word to describe him would be intense: He is dominant, proud, and willful, and often considers his way the best. The problem with his way is that it usually involves killing something, especially humans--despite somewhat mellowing over the course of Wolf's Rain, he is still a wild animal and should not be trifled with. He is often irritable and barely manages to restrain himself from violence, implying that he would rather attack than negotiate or run.
He is nowhere near a Gary Stu, as Kiba's author admits. Rather, she intends for him to be a realistic portrayal of both the "lone-wolf" stereotype and wolves in general. Being a wolf, he hates being alone; unfortunately, he has been alone for much of his adult life, and it has taken severe tolls on his mental state--well-adjusted wolves, including the pack he led to Paradise, have shown dislike for his sometimes-unnecessary violence. Despite it all, Kiba readily admits that any company is better than none. He forms very strong bonds after getting to know someone, and has proven himself a capable and devoted leader in the right conditions.
Kiba's true form is that of an Arctic wolf. His human illusion has messy black hair, fangs, and light blue eyes; the last aspect differs from the rest of his pack (which keep their amber wolf's eyes), possibly to reflect his white coat. He also "wears" jeans, sneakers, a white shirt, and a bomber jacket with the sleeves pushed up. Both forms are quite formidable, with his real form being three feet tall (five inches higher than the Arctic Wolf's maximum). At his peak weight he is about 120 pounds, but he is undoubtedly strong no matter what he goes through--in Wolf's Rain, he went a month with only the energy he gained from moonlight and was still able to bend steel bars with his teeth.
His injuries will be consistent in both forms; if he gets shot in the left shoulder, his human form will have a gunshot wound in the equivalent spot.
Before his appearance in the Sueniverse, he was searching for Paradise with three other wolves and the Lunar Maiden, Cheza--unfortunately, everyone died one by one before they could get there, with Kiba drowning in decades' worth of melting ice just before Paradise opened. Having to watch everyone else die has affected him greatly, and Cheza's death was especially traumatic. He inexplicably arrived alive in the foyer of the Opera House, and caused a minor trail of destruction on his search for the exit. He encountered the Phantom in the cellars, and met a werewolf (Devon Slater) in a hallway, who helped him find the way out.
Erik did not frighten Kiba, although he was rather unnerved that Erik smelled partially dead (being Leroux's original Phantom). Upon meeting Devon, Kiba noticed that he smelled like both a human and a wolf; as there were no werewolves in Wolf's Rain, he now considers werewolves to be inferior and is concerned about being the only "normal" wolf in the Sueniverse.
Le Rouge et L'Epine
His arrival at Le Rouge et L'Epine was unusual; he'd spent about two days wandering the forest and went to get some sleep in the moonlight near the building. Sirius, one of Brandi's puppies, came outside due to curiosity after realizing a wolf's scent was close to the inn. Due to Le Rouge's unlocked front door and the absence of Brandi (or anyone) to supervise the puppies properly, Kiba considered Le Rouge utterly lacking in security and elected himself alpha after taking Sirius back inside.
Shortly afterward, Helen of Troy arrived to ask for a room. As the newly-established leader in his mind, Kiba met up with her and was briefly mistaken for Zeus because of his ability to take human form and "speak" her language. Brandi came to meet Helen as well, and despite a near-fight with Kiba when he attempted to demote her, they straightened things out and he is now reluctantly her second-in-command. Despite his difficulty accepting that he must defer to someone (and a human at that), he admitted to himself that spending time with humans and dogs was quite preferable to being alone, and that Helen and Brandi made more sense than Erik or Devon.
Helen of Troy and Current Events
Helen of Troy asked Kiba to protect her from her enraged husband Menelaus, who wanted to kill her for running off with Paris and then escaping to the Sueniverse after the Trojan War. Kiba agreed as he was more than capable of the task, and Helen is one of the few humans he can (positively) tolerate so far. His reasons for accepting her request were at least partially because she reminded him of Cheza.
Tsume, one of Kiba's pack members, came to the Sueniverse as well. He found Kiba and Helen in A Much Nicer Hotel Than The Hilton and the three had to escape from Menelaus shortly after, who found them because of a coincidental request for a room there. They searched out Menelaus in the Elven Kingdom of Lorien for a while, and a run-in with the Wolfrider Starmane led to Helen getting shot. This turned Kiba totally xenophobic, and now he needs an extremely good reason to trust anyone out of the ordinary--especially not supernatural beings like vampires or werewolves. So far, he's managed to avoid further fighting by ignoring the fact that they exist.
Offscreen event: Helen vanished some time in 2009 (her author had to leave for a while due to family concerns), and Kiba has been searching for her nonstop. It is unclear why or even how it happened; there was neither a struggle, nor did strangers arrive before her disappearance. In Kiba's mind this is just another test of his willpower--which means he's either in denial, or he's finally going crazy. While he has recently found her, he'll probably take a while to recover from this.