Kurokitsune (literally Black Fox) is a Fire/Dark type Zanpakutou. The spirit of this zanpakutou is a large man sized black fox. It has 9 tails and has crimson red eyes. It's teeth are huge and pearly white.
When sealed, Kurokitsune is as a short Yari (Pole arm) with two blades protruding from the top edge. It has a black and red stripe design in the middle and a brown colored bottom.
The command for Kurokitsune is "Denpa Yaku!" (literally Spread Disaster). In Shikai, Kurokitsune goes from a Yari to a Naginata (another form of Pole arm). The shape of the Zanpakutou is a long pole with a short blade at the end. The long pole is red/black/and gray. In Shikai, Kurokitsune can release black fire from the blade. The sword can also create black fire copies of the user.
In Bankai, Kurokitsune (now Yajuukitsune) becomes a Nodachi (a Japanese sword). It has a thin blade and thick black handle. The user is know wearing a black coat with red fire marks on the bottom. Where ever they step there imprint will leave a black flame. The user also has the ability to fire ball's of fire at the target.