HG GPB-06F Super Custom Zaku F2000 1/144 (Model Suit Gunpla Builders Beginning G)

This is one loaded Zaku. The F2000 Super Custom, which appears in the OVA Gunpla Builders, wields that massive Deadend G Heat Hawk, as well as sub arms that hold a Super Custom MMP-80 90mm Machine Gun, and Super Custom MMP-78 120mm Zaku Machine Gun.
If that weren't enough firepower, he's got a machine gun mounted on his arm and missile pods on his shoulders!