Zwei/History

Background
Zwei is the pet dog of Taiyang Xiao Long and his daughters Yang Xiao Long and Ruby Rose. He normally lives with Taiyang at his home on Patch.

Sent to Team RWBY
Zwei is first introduced after Taiyang sends him through the mail to Team RWBY at Beacon Academy. Though Yang and Ruby are delighted to see him, Weiss Schnee and Blake Belladonna are not. After a few seconds, however, Weiss warms up to him and pets him. Blake tells the team to keep Zwei away from her belongings. Before heading to the auditorium to receive a mission, Ruby puts him into her backpack. The team leaves on a mission to Mountain Glenn with Dr. Oobleck, and once there, Zwei reveals himself to the surprised team. Dr. Oobleck commends Ruby for bringing Zwei along on the mission.

That night, Zwei leaves Team RWBY's campsite in Mountain Glenn to pee on the destroyed city. Ruby chases after him, and once she catches up to him, they hear voices. They discover them to be patrolling members of the White Fang, and the two follow the patrol to their base. On their way, the street collapses, and Ruby falls through. Zwei returns to the campsite to inform the rest of the team. He leads them back to the caved in street, and they travel underground to help the team's leader.

Once there, they reconnect with Ruby, and the White Fang leaves the underground via a train. Zwei and the rest give chase, and after boarding the train, fight off several White Fang members. After the White Fang members commandeer Atlesian Paladin-290 units, Zwei works with Dr. Oobleck to destroy them. Before the train busts into the end of the tunnel, Zwei takes shelter in a remaining Paladin.

Zwei exits the Paladin, now above ground in the city of Vale. He fights alongside teams RWBY, JNPR and CFVY to defeat the Grimm that have breached the kingdom's defenses. After successfully holding off the Grimm, Zwei and Team RWBY return to the dorm to rest. Episodes Covering These Events
 * "Field Trip"
 * "Search and Destroy"
 * "Mountain Glenn"
 * "No Brakes"
 * "Breach"