Bloodmantis
First appearing some time after humans begin deploying homegrown alien tech gear and stunning weapons, this creature is actually a heavily upgraded version of the bloodspider robot... but the resemblance to the terrestrial praying mantis is such as to cause the few surviving witnesses to wonder just how closely the aliens are studying other forms of life on Earth besides humans.
Structure: The bloodmantis is based on a larger, elongated version of the bloodspider chassis supported on four limbs near the front with an additional elongated body segment rearing up from above the front area where the harvested organs are stored. This near-vertical segment has a pair of "arms" near the top and is capped off with a triangular "head" equipped with variety of sensors.
To be clear, the harvested biomass is still stored in the front of the main section just as with the bloodspider so the apparent "mouth" would be where the two segments join. The upper segment "arms" and "head" mount weapons and sensors respectively.
(Stephen King, I've learned much from you...
)
Weapons:
Bloodsabre: The two "arms" each terminate in a sizable curved monomolecular blade and the blades can fold back against the "forearms" in a manner very akin to its terrestrial counterpart, but that's also where the bloodmantis sports a nasty surprise...
Shocker Gun: ... unlike the earthly mantis this folding action exposes the muzzles of a pair of electromagnetic projectile weapons buried in the "wrists" of the bloodmantis. These weapons hurl beads constructed of alien materials that are essentially flying Leyden jars... small capacitors charged up as they are fired from the weapon and delivering a stunning shock when they hit a target. The bloodmantis can adjust the strength of the charge imparted to each bead and thus can vary the shock as needed... from stunning a pesky Phalanx trooper to incapacitating a pesky Phalanx UGV.
And the bloodmantis is smart... it won't waste its beads on civilians when there are enemy combatants in the area.
Armed, armored and much tougher than the bloodspider... but has anyone got a better name for it than "bloodmantis"?