Kurama (九喇嘛) is the nine-tailed fox spirit sealed within Naruto Uzumaki. Prior to Naruto, his hosts were Naruto's mother Kushina and maternal ancestor Mito.
Brief history[]
Kurama was one of nine tailed beast "spirits" created by Hagoromo Otsutsuki when he split the chakra of the Ten-Tails into separate beings, each with an increasing number of tails. Kurama became infamous as a rampaging beast akin to a natural disaster, and so upon his defection from Hidden Leaf Village, Madara Uchiha sought to control the Nine-Tails as a weapon against his enemies. Madara was defeated by his enemy and former friend, the first Hokage Hashirama Senju, and Hashirama's wife Mito sealed the fox inside herself, becoming a host known as a Jinchūriki.
Mito's descendant Kushina was selected as the next Jinchūriki for Kurama as Mito's life neared its end. However, as Kushina was giving birth to her son Naruto, Madara's understudy "Tobi" took advantage of her weakened state and unleashed the fox spirit. Kurama rampaged once more, and Kushina's husband, the Fourth Hokage Minato Namikaze sealed half of the fox's essence in himself (the Yin portion) and the other half in the newborn Naruto (Yang half). With Kushina's last strength ebbed by the ordeal and Minato sacrificing himself to create the seal, Naruto was left orphaned.
TMNT x Naruto[]
Upon Naruto and the rest of Team 7 encountering Alopex, Naruto wonders if she has any relation to Kurama. Kurama pipes up from inside Naruto and tells him that she's not a tailed beast, and calls her a "one-tailed fox fake". TMNT x Naruto #1