Abumi Zaku, part of a team with Dosu Kinuta and Kin Tsuchi, is an arrogant and proud genin who stubbornly refuses to give up, even at the cost of his arms. This Sound ninja had a difficult life as an orphan, and was beaten regularly for stealing food to survive. Orochimaru then took him in because he "liked" Zaku's angry, proud eyes.
Zaku likely had a special surgery in his arms, giving him the ability to use his Zankuuha, a powerful jet of air that can destroy rocks and rip flesh. Although powerful, it has a glaring weakness, which is that it is clogged easily, as Zaku found out during his fight with Aburame Shino.