Killer B's Jinchūriki Forms

Kira Hachi is a Jinchūriki of the Eight-Tailed Beast. So far, he has only displayed two forms.

Jinchūriki Form
When need be, Kira Hachi will tap into the Eight-Tailed Beast’s chakra and generate a demon cloak similar in appearance to Naruto’s One-Tailed Transformation (and onwards). However, the demon fox's "ears" have been replaced with what appear to be bull-like horns.

Full Transformation
While fighting Sasuke Uchiha and his team, Kira Hachi managed to wound Sasuke long enough to transform into a full form. In this form, he takes on the appearance of the Eight-Tailed Beast itself, rather than just a cloak, appearing like a large ox with eight octopus-like tentacles.