The Super Synth/Soldier, a cut Half Life Character turned into a real thing in City-51, poor guy has a really bad foot which makes him a bit stiff.

With little detail with this character I decided to make up some shit myself.
The Super Synth is an Alien Race turned into a weapon, the creature is a slow walking tank, and quite literally a tank scaled down to fit through buildings, any sort of bullets cannot pierce the armor of the synth, though there are some gaps vulnerable to bullets.

Explosives are best used against this thing, just like any other armored synth, a few rpg rockets and it’ll go down within seconds.

But be well aware, it is armed with a gun and a cannon jammed into its right arm, firing off supposedly energy cells as well as an anti-matter ball