Akanbō

Akanbō (赤ん坊, Akanbō), more commonly known as the one of the Pseudo-Tails (もどき尾, Modokibi), is an "artificial" tailed beast currently sealed within Yasai of Konohagakure.

Background
Akanbō was created by an "unknown scientist" as experiment to recreate a Tailed Beast. By pushing the Curse Doll Technique over it's limits with almost a limitless supply of chakra, guided by the use of Yang Release Chakra, Akanbō was born. It's original purpose, along several other Artificial Tailed Beasts, was to destroy the Five Great Nations against their wills. The Hokage at the time, then sealed them into infant or young village children, in the hopes of enhancing their future militia. Yasai was chosen as it's host, giving apparent potential as a talented Shinobi.

Personality
Akanbō a very prideful tailed beast, as it detests all humans and usually reveals a cunning demeanor. According to Yasai, because of its innate rage and blood-lust, Akanbō relishes the opportunity to kill anyone in sight, even more so during a full moon. However, Akanbō is also incredibly childish and immature; he is very prone to taunting, and flies into a rage if he is teased enough.

Appearance
Akanbō is a golden-furred and purple-skinned monkey, with a body-build of a gorilla. It has eyes with pink irides and white pupils, and green spike-like protrusions along it's shoulders and back.

Abilities
Akanbō has the ability to simultaneously use the lightning and water natures, to use Storm Release. As its jinchūriki, Yasai can borrow its ability to create and use Storm Release techniques.

Activity inside Yasai
As he has little to no control over Akanbō, Yasai is easily prone to Akanbō's influence, easily losing control. However, Akanbō somewhat acts as his partner in battle, disturbing his chakra in order to break illusions cast from even the Sharingan, as well as give Yasai advice and chakra in battle.