Chaka

Chaka, also known as "Chaka the Jackal", is one of two head guards in the Arabasta kingdom that serve under Igaram; the other being Pell. Chaka is the acting captain of the royal guard in Igaram's absence. He ate the Inu Inu no Mi, Model: Jackal, a Zoan-type Devil Fruit that allows him to transform into a jackal or a human/jackal hybrid.

Most often Chaka was with Pell, but during Sir Crocodile's attack on the Kingdom, he left to attack him. Because of Crocodile's actions and lack of compassion, Chaka was angered to the point that he attacked Crocodile out of rage, but his reasons were also backed by an attempt to protect Vivi and Kohza, as well as buy them time to put an end to the battle - but despite his efforts, he was easily defeated. He survived, however, and showed up later on in the Arabasta arc commanding the royal guard to stop fighting, and later appeared at Pell's grave.

His latest appearance was during the time when the Straw Hat crew recieved their bounties shortly after the CP9 arc, somewhat shocked to see Robin in the Straw Hat crew.

(Source: One Piece Wikia)