Raika is a supporting character in the anime Plus-Sized Elf. She is a werewolf, also referred to as a lycanthrope, who crossed over from another world to Earth. Her most notable ability is shapeshifting: she can transform at will between a humanoid anthro form and a full wolf form. However, in her wolf form, many people mistake her for an ordinary dog, and this misunderstanding shapes much of her experience in the human world.

Because humans saw her as a friendly stray dog, they began giving her food in large quantities. She received an abundance of high-calorie offerings and, as a result, grew noticeably heavier after arriving on Earth. Her weight gain is compounded by her own habits: humans brought her more food than she could handle, and she cannot bring herself to save any of it for later. Her appetite therefore works against her even when the consequences become obvious.

Raika fits the general description of lycanthropes in her world of origin. They are portrayed as a common species that is hard to please and difficult to deal with. Because they stand near the top of the food chain, they are also said to carry considerable pride. Raika embodies this combination of stubbornness and pride in a way that the story treats mostly for comedy, as a fearsome predator is constantly reduced to the image of a well-fed pet. She is a creature of appetite who tends to give in to food rather than resist it, and her reactions to being doted on by humans provide much of the humor in her appearances.

Her role in the story is that of a supporting figure rather than a member of the central cast. In the anime, she is introduced in the fifth episode alongside Oku, an orca who also comes from the fantasy world, and the sequence highlights how beings from that world adjust to the abundance of modern human life. Raika's key relationship is with humans in general: instead of seeing her as a predator, they treat her as a cute, food-loving animal, and her inability to turn down what they offer keeps her weight as an ongoing part of her situation.

Because she is a supporting character, the narrative does not focus heavily on her personal growth. Her development is mostly limited to the running joke of a proud lycanthrope being pampered and overfed by well-meaning humans. Her notable abilities remain her voluntary transformation between humanoid and wolf forms, along with the physical traits of a top predator inherited from her species, even though the story more often emphasizes the gap between that fearsome heritage and the way others actually perceive her.