Zwei/Affiliation

Taiyang Xiao Long
Taiyang is Zwei's owner.

Ruby Rose
Zwei appears to love Ruby very much as he affectionately licking her in "Field Trip".

Blake Belladonna
At first, Zwei wants to get along with her, but she tries to avoid him.

Yang Xiao Long
Not much interaction between them, but he and Yang has a friendly and playful relationship.

Bartholomew Oobleck
When he first met Oobleck in "Search and Destroy", he manage win over and let him stay with the group. They even work great together during the fight against the White Fang in "No Brakes".