A wolf is a large canine. Wolves usually serve Lupa, the leader of Camp Jupiter. Wolves are social predators that generally live in families or packs, although they do sometimes live alone for various reasons. In areas where human cultures and wolves both occur, wolves are frequently featured in the folklore and mythology of those cultures, both positively and negatively.
Jason Grace has a dream where he stands in Redwood Forest, and a pack of wolves circle around him while the ruins of a stone mansion arise. The wolves eventually lead him to Lupa, who gives him hints to his past and makes a joke that hinted about his identity as being Jason Grace.
Later on, a group of lycanthropes attack Jason, Leo Valdez, Piper McLean, and Gleeson Hedge. They are led by Lycaon, the first werewolf, and according to him, they are the enemies of Lupa and her pack. Lycaon also harbors a grudge against Zeus and his children for turning him to what he is. The Hunters of Artemis scare them off or kill them with their silver arrows, silver being the only metal that can kill them.
It is also shown that the Hunters of Artemis have their own pack of wolves that they use for hunting and tracking. It also appears they have some level of communication with them, most likely from being a hunter.