Jubi

The Rikudo Sennin facing the ten tailed beast, the Jubi.]]The Jubi is the ten tailed Beast, a fusion of all nine other tailed beasts. According to Uchiha Madara, it was defeated by the Sage of Six Paths (Rikudo Sennin) by sealing the beast's chakra within his own body, and splitting its chakra into the nine tailed beasts upon his death. The body of the Jubi was also sealed by the Sage and sent into the sky, thus the "moon" he is said to have created. All that has been seen of the Jubi is a large, Kyuubi-like outline, with a single, large eye that appears to be a mixture of both Sharingan and Rinnegan. Considering it is a fusion of all the beasts, it can be reasonably assumed that the Kyuubi is only a full fifth of the Jubi's power.