Board Thread:Theories and Speculation/@comment-5119417-20150523231237

It is possible for a ten-tails spore to still be alive. Lets go all the way back to the 4th Shinobi war, Naruto and Sasuke putting the Ten-Tails on fire with the Amaterasu. The Ten-Tails separates its body part from the flames.

From what has been said about Amaterasu, it burns for seven days and nights. However, it also says that "the jinchūriki of the Ten-Tails can't be burned by the flames". This is saying that the Ten-Tails' skin acts as a defense.

So it could be possible that the piece of flesh the Ten-Tails separated survived and has taken on the form of this tiny creature. And if possible, Kaguya is manipulating it and is working together with the two Uchiha. 