Akuta is an Earth Release technique that's created from a Land of Earth's kinjutsu, which is seemingly inspired by a jutsu that was unearthed by Ōnoki. It was a technique designed by Ōnoki to protect the village from attackers while lowering the number of casualties.
The Akuta creates living organism made of clay that are weaponised. They are able to phase through the earthen ground for travel and drag their enemies with them, as well as extend their limbs. While they have no fear, they have a limited lifespan and intelligence, being capable of obeying instructions and communicating with fabrications. Their masks are their weaknesses, destruction of which would lead to their deaths.
While deemed to have no will, this was prove false in Akkun's existence, a small Akuta who gained affection to Inojin Yamanaka, and even defied its comrades to protect him. Kirara deemed Akkun as a defect for such traits. When the fabrications decided to take matter into their own hands, the Akuta produced even went against Ōnoki's orders.
Ōnoki created this technique in response to a missing-nin's attack claiming the lives of many young shinobi. When he first demonstrated it, they suddenly disobeyed him and attempted to attack the audience, which led Kurotsuchi to reject the technique's further development. Despite this, Ōnoki continued to hone this technique in secrecy, eventually managing to create more obedient creatures.
Iwagakure housed an underground facility where more Akuta are being mass produced. It was later destroyed by Konohamaru Sarutobi.