Seven

Seven is an over-extend Gun Slave Unit that works for Beruhren. He is also operated by Pepper.

Seven is similar to Juzo Inui in build. Like Juzo his most distinctive feature, is the gun he has for a head. His head is a desert eagle, with the trigger in the back. Under it, is his prominent metal chin, with an extra row of teeth in the jaw.

(Source: No Guns Life Wiki)