The nine tailed beasts in Naruto were split from Kaguya Otsutsuki's sacred tree. The Sage of Six Paths personally named them when he divided the ten-tailed beast using Yin-Yang Release. There are technically ten tailed beasts, but the zero-tail is excluded as it only appeared in the movie version. Despite not being part of the comics, it is still considered a tailed beast.
Unfortunately, the zero-tail had a miserable ending as it lacked intelligence and thoughts like the other tailed beasts. Naruto and Sasuke eventually weakened and killed it by inputting excessive chakra, similar to myths. Its appearance is extremely ugly, making it difficult for most people to see it as a tailed beast.