This is a variation of the Kargan "Mauler" Mekton (from R. Talsorian Games' "Mekton II") that I came up with for fun.
It ditches the flightpack, replaces the leg verniers with jumpjets, wields a more powerful 150mm handheld cannon, and adds a shield and two missile launchers. (The launchers are mounted on the backpack, not on top of the shoulders. That way, the arms can move around freely without affecting the firing arcs of the missiles.)
The flight-capable version can be found here: [link]
Lineart can be found here: [link]
Just to be safe... The Mauler is the I.P. of R. Talsorian games. No infringement intended nor implied, etc etc etc.