Alien Grunt

The Alien Grunt is a species from a dimension named Xen (pronounced as "zen"), known only by their ranks. Their origin is unknown, but many guess they are a species of Vortigaunts  which evolved into fearsome brutes, or, they are Vortigaunts which joined Nihilanth. Though they are actually another species of the same genus. Their anatomy is akin to a Vortigaunt, except they have a hornet gun attached to their hand, they have three same-sized eyes, and are taller than an average human.

Trivia

 * Their taxonomic designation, "Xenotherium myrmex" means "alien ant beast".