The Hungry Wolf is a dangerous but unlucky wolf who is constantly met with misfortune during several encounters with Wart (aka Arthur Pendragon). He tried to eat Wart several times in the film. Of course, he always misses and is injured frequently. He is a scrawny wolf who is more comical than threatening. He also bears a resemblance to the Wolf from Peter and the Wolf, though he is not as frightening.
The wolf finds Wart in the forest, and decides to abandon an old bone in favor of having this boy for a meal. He tries and fails to eat him. The last time being when Arthur and Merlin turn themselves into squirrels. He ends up being defeated by a female squirrel who fell in love with Arthur. She tricked him into jumping into the river, where he ended up stuck inside in a log, floating downstream, and is never seen again in the rest of the film.
Unlike most non-speaking villainous animals who are frightening in appearance, the wolf is the only animal who is not. He appears slightly powerful, but he is mostly dumb, ugly, and rather unlucky.
The wolf is similar to the Wolf in Make Mine Music in that they both want to eat humans and/or animals, and they both fail miserably. Except that MMM's wolf is more frightening, and yet more challenging for the protagonist to defeat.
The wolf is the second villain to appear in The Sword in the Stone. The first one is the hawk during the prologue of the movie.