Are you talking kurama in sixtale mode or Saiken because if you arehere something about him (犀犬, Saiken), more commonly known as the Six-Tails (六尾, Rokubi), is a tailed beast sealed within Utakata of Kirigakure. It has been captured by Nagato in the anime, then extracted and sealed by Akatsuki. It was later resealed into a reincarnated Utakata during the Fourth Shinobi World War
Saiken resembles a large, white with a slight light blueish tint, bipedal slug with stubby arms and feet. It has two prominent optical tentacles (eyes) and hole-like openings as a mouth. Its entire body is covered in a slimy substance.