Zwei is the pet dog of Ruby Rose and Yang Xiao Long. He first appeared in the episode "Field Trip", when he was mailed to Beacon Academy from Patch by Taiyang Xiao Long along with a pile of canned dog food and a can opener.
Tai sent Zwei to his daughters to take care of him temporarily due to him leaving Patch for undisclosed reasons.
Zwei is a black-headed tricolor Pembroke Welsh Corgi with gray eyes. Like some Pembroke Welsh Corgis, he has a bobbed tail, which is nowhere near the length that would indicate him as being a Cardigan Welsh Corgi. As of "Of Runaways and Stowaways", he wears a red collar with a gold pendant bearing a vertical black bone and two black dots on either side.
Zwei exhibits a very cheerful and playful personality, as seen when he licks Ruby and barks happily after Weiss Schnee cuddles him. He also playfully imitates Yang's behavior.
Zwei is shown to be very intelligent for a dog. Not only does he react appropriately to Ruby's commands, he also seems to be smart enough to use mechanical tools. When Weiss wonders how Zwei will eat his canned dog food and a can opener drops out of his tube, Yang cheerfully drops the issue, implying that Zwei can use it.
Powers and Abilities
Zwei is a very intelligent dog, implied by Yang to be capable of using mechanical tools such as can openers and responding correctly to Ruby's questions when needed. As a dog, he has heightened senses of smell and hearing, which allowed him to find the White Fang soldiers in "Mountain Glenn".
Likely due to his Aura, Zwei has been shown to perform feats no normal dog can do. He was first introduced compressing himself into a tube alongside dozens of cans of dog food and a can opener for an undisclosed amount of time without any ill effects on his body.
Later, in "No Brakes", he is shown to be fireproof and extremely durable, as seen when he destroys an Atlesian Paladin-290 by being lit on fire and launched by Oobleck. This is demonstrated once more in "Breach", where he survives the train explosion by taking shelter inside a Paladin, then proceeds to headbutt and defeat a nearby Beowolf.
- His name is likely a reference to the Cowboy Bebop character, Ein, who is also a Pembroke Welsh Corgi, though of a different coloring. Eins is the German word for "one" while Zwei is German for "two".
- In the credits of "Breach", Mrs. PennyApple and Penny Layne Matthews are credited as Zwei's voice actors. Said dog is Meg Turney's Dachshund, Penny.
- Kerry Shawcross was very adamant on having Zwei's butthole on the model for RWBY Chibi, due to its comedic value, going as far as to ensure that it was included on Zwei's chibi merchandise. "Zwei Painting", one of the shorts in the 10th episode of RWBY Chibi, "Love Triangle", also focuses on Zwei's posterior.