Raven is a Native-American who can turn into a raven and is guided by his animal spirit. He refers to himself as a trickster figure, which is true to the mythology. During his time as a prisoner at the Golden Boughs, he became friends with Wicked John and once tried hitting on Mary Quite Contrary. At some point, the spirit instructed him to stay close to the copy of Jack of the Tales. Raven, like so many others, Raven believed that Wicked John, who was the spitting image of Jack except from his dark hair, was a copy of Jack Horner, and Raven and John became close friends. After the mass escape from the Golden Boughs, it was revealed that John was the original Jack of the Tales and that Jack was actually the copy. After hearing the news, Raven chose to leave John behind and become Jack's companion instead, since the spirit had specifically instructed him to befriend the copy and not the original. Staying true to the trickster figure mythology, he was close to turning his back on Jack more than once when trouble arose, an example would be in Americana arc after Jack pushed him off the train during a treasure hunt.
He bumped into Hillary Page and Paul Bunyan, whom he nervously spoke to(due to he had helped Jack push them out of the train) that he couldn't be too mad at Jack. He had planned on doing the same. And while going through the American Fabled Homeland, he abandoned Jack and the group when they came upon Native Americans. And another example is when Hillary becomes angered by Jack's confession of sleeping with her other sisters. Raven admits he'd would have done the same, but he wouldn't have admitted it aloud to. He saw it as bad form.
But despite his anger towards Jack, he still helped him. Mainly because his animal spirit threatened and nagged him into submission. Jack and Raven's ways eventually parted after the destruction of the Golden Boughs, when Raven chose to stay with a group of former prisoners. He and the Fables stay, at the dinner eating. Apparently over the years they had been forgotten. And at some point they turned the diner into a theme park where the Fables worked.
Decades later, in the final story arc of the series, the spirit comes to Raven in a dream and tells him that he has forgotten his purpose in life, which is to protect Jack Horner. The spirit commands him to gather together every ally he can muster and save Jack Horner, who, unbeknown to Raven, has been transformed into a dragon. Raven tells the others that the bird spirit has showed him the way to Fabletown, and the group sets off to find the place. The group follows the spirit for days, until they reach their destination, finding themselves in the middle of a battle Jack Frost II and Jack the dragon. Raven lies to the others and convinces them to protect the dragon, saying the dragon is the only one who knows the secret way to Fabletown. Everyone soon realizes that they have been tricked when Jacks kills several of them, believing that they are out to steal his treasure. The Page Sisters also show up, and are devastated when Jack burns the books of original Fable stories that they have been looking for. Upset at the loss of the books, they start shooting everyone around them and Raven is shot through the head. As he dies, he asks the spirit why it lead them into this death trap, to which the spirit replies, "No particular reason. I thought it'd be funny".