Black pack

Jacob Black's Pack is a pack of shape-shifters. It is led by Jacob Black, and his second-in-command is Leah Clearwater. This pack was formed when Sam Uley and his pack planned to kill Bella and Renesmee in Breaking Dawn to prevent any potential danger that could affect their tribe and the people of Forks. Seth and Leah Clearwater joined when they thought they would rather be led by Jacob. This pack was instrumental in helping the Olympic Coven protect Bella Cullen when she was pregnant with Renesmee Cullen.

By forming a pack of his own, Sam and his pack were compelled to keep an eye on the Cullens and make a decision as to whether or not Renesmee should die after she was born. Jacob and Sam's packs resolved their tension after Jacob imprinted on Renesmee, because they had a law that prohibited them from killing anyone the wolf had imprinted on due to the effect it had on the wolves.

Afterwards, Jacob's pack claims the protection of Forks and the Cullens as their jobs.

This pack stood beside the Cullens during the confrontation with the Volturi, who mistook Renesmee to be an immortal child. They were also joined by Sam's pack and wolves from other tribes. Caius' accusation of the vampires' partnership with the werewolves made Edward reveal the fact that the members of the Quileute tribe were actually shapeshifters with the ability to change into wolves, and not real werewolves.

Members
After Jacob decided to fulfill his Alpha duties, wanting to protect Bella, he broke away from Sam Uley's pack and went off on his own. A little while later, Seth Clearwater started following him because of his respect for the Cullens, with whom Jacob began spending the majority of his time. Two days later his sister Leah joined them in order to stay away from Sam and watch out for Seth. During their time with the Cullens, Leah and Jacob formed a friendship and Leah eventually became the second in command of the pack, also called the "Beta" by Bella Swan when she was trying to understand pack politics. Jacob imprints on Renesmee and this resolves the tension between the two packs, Quil and Embry joined Jacob's pack as well.