Who is Wolf in "Rip Van Winkle"?

Wolf is Rip Van Winkle’s loyal dog. He is an "honorable" and "courageous" animal who accompanies Rip on his walks in the woods and mountains. However, Rip’s wife does not like Wolf; she believes that the dog is as lazy as his master and considers the two of them "companions in idleness." Although as brave as can be when out with Rip, Wolf is terrified of Dame Van Winkle and her "evil eye":

The moment Wolf entered the house, his crest fell, his tail drooped to the ground, or curled between his legs, he sneaked about with a gallows air, casting many a sidelong glance at Dame Van Winkle, and at the least flourish of a broomstick or ladle, he would fly to the door with yelping precipitation.

Rip, for his part, is well-liked by the villagers due to his kind nature. The children of the village adore him because he loves to spend time with them; he teaches them games, builds their toys, and tells them interesting stories of old. The village women often employ Rip’s help to complete various tasks, such as running errands and doing odd jobs. Rip enjoys helping his neighbors, and he is appreciated in this regard. However, Rip is not as industrious in completing profitable work on his farm. Thus, his wife constantly nags him, as she feels that Rip’s laziness is the reason for the family’s poverty and blames Wolf for leading Rip astray. Rip therefore pities Wolf as a "fellow-sufferer" of Dame Van Winkle's "persecution," and this feeling seems to bring the two of them closer together; "if dogs can feel pity," Irving writes, then Wolf surely pities Rip "with all his heart."

As the story goes, Rip goes hunting in the Catskill Mountains with Wolf one day to escape the constant nagging from his wife. After drinking liquor from the keg of some strange men he meets in the mountains, Rip falls asleep for twenty years. When he finally wakes up and sees that Wolf is not with him, he initially thinks Wolf must have simply run off after a “squirrel or partridge.” Rip then walks back to the village, where he finds "a half-starved dog" resembling Wolf outside his house. Sadly for Rip, the dog does not recognize him and snarls when Rip calls his name.

Who is the narrator of "Rip Van Winkle" by Washington Irving?

Washington Irving had a genius for inventing comic fictional narrators.  In fact, he did not sign his real name to his work until he was over fifty.  He had two narrators, Jonathan Oldstyle, Gent., a caricature of the British writers who could not accept the simple values of the new nation, and Diedrich Knickerbocker, a Dutchman. He it is who leaves the tale of Rip van Winkle, and the story is framed by an unknown writer.

Irving writes,

The following tale was found among the papers of the late Diedrich Knickerbocker; an old gentleman of New York, who was very curious in the Dutch history of the province, and the manners of the descendants from its primitive settlers.

Because Knickerbocker was known for his "scrupulous accuracy," the unknown writer states, the tale of Rip van Winkle should be taken as entirely accurate.

Who does the narrator sympathize with in "Rip Van Winkle"?

The narrator seems to sympathize a lot with Rip Van Winkle. Rip certainly has characteristics that could (and did) get him lectured by his wife, like his avoidance of profitable labor despite his willingness to work in other ways, but overall the narrator portrays Rip Van Winkle in a positive light. He has strong relationships with the people in his town, including the children who often follow him around to listen to his stories. He is patient, kind, and isn't picky about most things; he is always willing to help a neighbor with even difficult tasks and is otherwise perfectly content in his relative idleness. The narrator also expresses a lot of sympathy toward Rip for his marital situation, and paints his wife in a comparably unfriendly light.