The Nine Masked Beasts are entities created by Menma through the use of the Black Nine-Tails' chakra. Five of these beasts are described as divine beasts (神獣, shinjū), while the other four are referred to as divine priests (神官, shinkan).
Menma summons them by forming a tiger seal, declaring "Nine Mask Svāhā" (「九面蘇婆訶」, "Kumen Sowaka") and chanting the kuji-in, which conjures a massive mandala featuring each kanji of the kuji-in encircled by nine rings, arrayed in the same cross pattern he wears on his cloak. Each of the masked beasts emerges from a specific ring.
- Seiryū (青龍, literally meaning: Azure Dragon), a dragon that resembles a seahorse. Emerges from the ring bearing the kanji 青 (sei, "azure").
- Byakko (白虎, literally meaning: White Tiger), a lean and slender tiger. Emerges from the ring bearing the kanji 白 (byaku, "white").
- Suzaku (朱雀, literally meaning: Vermilion Bird), a bird with elegant and dramatic plumage. Emerges from the ring bearing the kanji 朱 (shu, "vermilion").
- Genbu (玄武, literally meaning: Black Tortoise), a tortoise with a shell made of overlapping plates. Emerges from the ring bearing the kanji 玄 (gen, "black").
- Kinja (金蛇, literally meaning: Golden Snake), a massive serpent with golden scales. It can bind opponents by wrapping its body around them. Emerges from the ring bearing the kanji 空 (kū, "sky").
- Tennyo (天女, literally meaning: Celestial Maiden), an angelic priestess with flowing robes. It uses translucent ribbons to whip at opponents. Like the Kinja, it can also bind opponents. Emerges from the ring bearing the kanji 玉 (gyoku, "jewel").
- Shinigami (死神, literally meaning: Death God), a priest that resembles a skeleton and carries a scythe. A swing of this scythe unleashes sickle-like energy waves which drain targets of their chakra once they have passed through them. The waves can bypass the barriers set up by Hakuto Sennin and Nanto Sennin. Emerges from the ring bearing the kanji 三 (san, "three").
- Hokuto Sennin (北斗仙人, literally meaning: Northern Sage), a priest with a fox staff. In unison with the Nanto Sennin, it can trap opponents in purple cylindrical barriers. Emerges from the ring bearing the kanji 北 (hoku, "north").
- Nanto Sennin (南斗仙人, literally meaning: Southern Sage), the matching counterpart of Hokuto Sennin. In unison with the Hokuto Sennin, it can trap opponents in purple cylindrical barriers. Emerges from the ring bearing the kanji 南 (nan, "south").
When defeated, they revert to their true forms, which are nine masked fox kits (子狐, kogitsune) that each possess a single tail. They can also convert back into chakra that will arc through the air from their present location back to Menma. Once they collide with Menma, they reform into the Black Nine-Tails.
- While summoning the Nine Masked Beasts, Menma refers to svāhā (薩婆訶, sowaka), a Buddhist term roughly meaning "calling" which is used in mantras. He also chants the kuji-in, which are featured as kanji on nine of the rings worn by the Akatsuki members.
- Among the Nine Masked Beasts, four of the divine beasts are based on the Four Symbols, a set of Chinese constellations, and two of the divine priests are based on the heavenly messengers and death god of Japanese folklore. Kinja, which somewhat resembles Huang Long, and Hokuto Sennin and Nanto Sennin, which are named after the Northern and Southern Dippers, are original concepts designed to round out the group. The nine kanji from the portals that the nine beasts emerge corresponds to the ones on the rings Akatsuki members wore.
- From top to bottom and left to right, the circles from which the beasts emerge are ordered: 玉 (gyoku, "jewel"), 朱 (shu, "vermilion"), 南 (nan, "south"), 青 (sei, "azure"), 空 (kū, "sky"), 白 (byaku, "white"), 北 (hoku, "north"), 玄 (gen, "black"), and 三 (san, "three").
- 空 (kū, "sky") is larger than the others and lies in the center of a larger empty circle. Along the circumference of this empty circle lie 南 (nan, "south") above, 北 (hoku, "north") below, 青 (sei, "azure") on the left, and 白 (byaku, "white") on the right. 青 (sei, "azure"), 空 (kū, "sky"), and 白 (byaku, "white") lie along the same row.
- Interestingly, the orientation of the circles appears to be reverse that of the traditional. In Menma's mandala, "north" (北) points south while "south" (南) points north. In addition, the Four Symbols traditionally have Seiryū (青龍) east, Byakko (白虎) west, Suzaku (朱雀) south, and Genbu (玄武) north; these are flipped for the Nine Beasts. Kinja (金蛇), which could be considered to be a parallel to the Huang Long, emerges from the central circle, which conforms to tradition.
- The seahorse-like appearance of the Seiryū may have been based on one way of saying "seahorse" in Japanese, which literally means "baby dragon" (竜の落し子).
- Menma uses the Nine Masked Beasts to overwhelm his opponents with numbers, similar to Naruto's use of the Shadow Clone Technique or Nagato's use of the Six Paths of Pain.
- Creation of All Things
- Six Paths of Pain
- White Secret Technique: The Chikamatsu Collection of Ten Puppets
- Naruto Stealth Volume: Road to Ninja (ＮＡＲＵＴＯ―ナルト―巻ノ忍 ＲＯＡＤ ＴＯ ＮＩＮＪＡ, Naruto Maki no Shinobi: Road to Ninja) page 77