Shukaku is a sandy-brown colored tanuki, with dark blue cursed seal markings all over its face, body, and tail. It has a jagged, concave mouth with no tongue, and the sclera of its eyes are black, with yellow irises and pupils that each takes the shape of a black four-pointed star with four black dots around it.
Shukaku is characterized as a wild and short-tempered individual, and often speaks in a bombastic and incoherent manner, giving it the demeanor of a drunken madman. It also expresses pride as it uses "ore-sama" (Literally meaning: my esteemed self) when referring to itself, and holds great confidence in its own abilities, especially its absolute defense. According to Gaara, prior to its introduction, Shukaku relishes the opportunity to kill anyone in sight, even more so during a full moon. Like all tailed beasts, Shukaku has shown a strong desire to preserve its own life, granting its jinchuriki the power to control sand as well as allowing them to transform into it in a state of need and blood-lust.
Shukaku harbors a bitter grudge towards Kurama due to the latter's beliefs that the tailed beasts' strength is measured by the number of tails, and thus Kurama views Shukaku as the weakest. Because to this, Shukaku will find any opportunity to surpass its arrogant rival.
Shukaku's hatred towards humans led it to spark fear in Gaara, reminding him that if he goes into a deep sleep, the tanuki would possess his body and murder all humans, resulting in Gaara's developing insomnia. Shukaku once had that similar attitude toward Bunpuku, but when its jinchūriki treated the tanuki as an equal, an impressed Shukaku complimented him by comparing him to the Sage of the Six Paths. During the Fourth Shinobi World War, Shukaku eventually saw Gaara in a similar light, being reminded of Bunpuku.
Sand Manipulation: Shukaku's most notable ability is its sand manipulation, using it as an effective weapon and shield. Since its whole body is completely made of sand, the tanuki can ignore most damage that would otherwise be detrimental, as shown when it had one of its arms chopped off by Gamabunta and was still able to keep on fighting. Taking pride in its motto of absolute defense, Shukaku's sand is durable enough to block a senjutsu-enhanced Susano'o sword with ease. It is capable of performing fuinjutsu by using its natural cursed seal markings across its own sand body, which gives off a magnetic field to bind its targets. One of its techniques, the Grand Sand Mausoleum Seal, is strong enough to temporarily restrain and withstand powerful techniques, like the Susano'o.
- Gaara (Jinchuriki)