A mech, sort of a cross between a Zaku II and a Gafran. Sorry for the sideways pics at the bottom.
About this creation
Chest, very Gafran.
Legs, the upper half based on the Gafran and the lower on the Zaku.
Gafran-style head. One concept was based more on http://ultra.wikia.com/wiki/Grozam.
Hand and grenade launcher.
It can fit a minifigure, in fact this whole creation was built around this Nexo Knights piece.
With a pilot.