Akkun

Akkun was unique among the Akuta. It has very little aggressive tendencies. More akin to a child, it was shown to be playful and curious at the world around it. It had also shown a strong attachment to Inojin Yamanaka, possibly imprinting on him as a surrogate parent, as it liked to remain around Inojin as much as possible. It however was nervous at meeting other beings and was prone to lash out. Akkun was shown to have a measure of sentient intelligence, as it was very particular on how it was referred to and was capable of talking and learning names, provided they aren't too difficult. Its childishness aside, Akkun was very brave and loyal, as its first instinct was to protect Inojin even against much stronger foes.

(Source: Narutopedia)