Viper (XCOM2)

The true form-- or at least directly/genetically related-- to the previous war's Thin Man, this species appears unmodified due to the aliens no longer needing an infiltration unit. They have a high movement rate, so beware flanks. Not that they need to flank: as relations to the Thin Man, they have the capability to spit poisonous acid with pinpoint accuracy. Keeping their snake-like form, they have a long, prehensile tongue capable of grabbing anybody from afar, and can constrict tightly around a victim.

And the case appears to be: yes, those are venom glands.