- Juubi, the Ten-tails, is a reference to Ame-no-hitotsu-no-kami, the Shinto god of iron-working and blacksmiths, DataraDatara, and/or DaidarabotchiDaidarabotchi. The former for it's ability to forge living thing out of metal and the latter for giant size.
- Kyuubi: 九喇嘛 (クラマ; Kurama), the Nine-tails, is a reference to the kitsunekitsune in Japanese mythology. The name Kurama probably named after the mountain in Japan. It is said to be home of the Tengu God Sojobo and, more importantly, the location where the technique Reiki was first learned. Reiki is the art of using chakra (universal energy) to heal other people. This ties into Naruto's life-giving energy ability he gains after tapping into the nine-tails chakra.
Hachibi: 牛鬼 (ぎゆうき; Gyuuki), the Eight-tails, is based off the Ushi-OniUshi-Oni, a sea creature commonly seen with an ox head and the body of another multi-limbed creature. The name Gyuuki (cow demon) is another pronunciation of Ushi-Oni.
Nanabi/Shichibi: 重明 (ちようめい; Choumei), the Seven-tails, is probably based off the rhinoceros beetle which are said to be amongst the strongest creatures on the planet in relation to their own size. The name most likely is a reference to Kamo no Choumei, a 12th century poet who secluded himself on society, took Buddhist vows, and became a hermit living outside the capital. Choumei is most famous for his writings that were mostly about nature and natural events. If you recall from the manga, two of the previously unseen captured Jinchuuriki's were outcasts that were abandoned by their village when Akatsuki came to capture them.
Rokubi: 犀犬 (さいけん; Saiken), the Six-tails, Saiken is based off the turban-shell snail demon, Sazae OniSazae Oni. The name comes from a compilation of Chinese legends called "In Search of the Supernatural". The Saiken (犀犬) in one of the stories (地中犀犬) is a type of dog-like creature with closed eyes, the size of small dogs, that like underground in pairs (male and female).
Gobi: 穆王 (こくおう; Kokuou), the Five-tails, is a reference to the the hanging horse head demon, SagariSagari, and the ghost whale demon, BakekujiraBakekujira. Typically Kokuou translates to "king" (国王) in Japanese, referring to a "lesser king," one below the emperor. The name probably is a reference to the Chinese legend of King Mu of Zhou (周穆王).
Yonbi: 孫悟空 (そんごくう; Son Gokuu), the Four-tails, is a reference to the Satori, an ape-like creature that can read minds. The name Son Gokuu is obviously a reference to the Monkey King in Journey to the West.
Sanbi: 磯撫 (いそぶ; Isobu), the Three tails, is probably based of a combination of the spirit of eaten-turtles that haunt those that harmed it, Suppon no YureiSuppon no Yurei and/or the amorphous sea monster, UmibozuUmibozu. Isopu is probably a reference to the shark-like demon sea monster with a barbed tail fin, IsonadeIsonade.
Nibi: 又旅 (またたび; Matatabi), the Two-tails, is a referenced to the forked cat demon, NetomataNetomata. Matatabi is named after the Silver Vine or Cat Powder a plant herb similar to a hardy kiwi vine. Used as a healing herb for cats and affects them in a similar way as catnip. When ground up, it is used in herbal teas and bath salts.
Ichibi: 守鶴 (しゆかく; Shukaku), the One-tail, is a reference to the shapeshifting racoon demon, TanukiTanuki. The Naruto One-tail bijuu shares several tanuki archetypes. One is from the Bunbuku Chagama tale, where a tanuki transforms into a tea kettle. In the series, the One-tail is said to have been sealed within one. Other versions of the taunki tale tell of the shrine priest being a tanuki in disguise, which ties into how the One-tail was supposedly corrupted a Hidden Sand priest. The name "Shukaku" probably refers to the priest of this tale.