Darkyubi is an enhanced Kyubi with a darker coloration. He is a silver fox with very long, dark purple claws. He has pale violet eyes and light blue facial markings. His inner-ear is dark indigo and grape. His wrist, lower body, tips of tail, fur around the neck, and ear-tips are dark grey. Attached to the fur of his neck are four thin, long curled strands of milk-blue. He is seen holding a bright violet and indigo flame, versus the red flames that normal Kyubi wields.
Befriended:"To embrace the darkness at such a young age... I approve!"
Being traded:"Hee hee! A profound despair begins now! You'll regret choosing me!"
Recieving food (favorite):"Tasty! Like gloom!"
Recieving food (normal): "Hmm... Intriguing."
Recieving food (disliked): "Ugh. Take it away!"
His Japanese name, "Yami Kyubi", translates as "kyūbi of darkness".
His English name, "Darkyubi", is a portmanteau of dark and Kyubi.
His Brazilian Portuguese name, "Trevoso" is a combination of trevas (darkness) and the suffix "-oso", that means that something "-has a lot of".
Darkyubi can be seen as a counterpart to Illuminoct: they resprent light and dark, and are recolors of Kyubi and Venoct who are also counterparts. In Yo-kai Watch 3 they are exclusive to the alternate versions.