Robber Fly

Robber flies are characterized by their spiny legs that sport stout femurs and tarsi with two claws; a mustache of dense bristles facially known as the mystax, positioned above the mouth and below the vibrissae (the stout bristles on the face below the antennae); three simple eyes (ocelli) in a relatively deep depression between two large compound eyes; and short, 3-segmented antennae that in some species sport a bristle-like structure (the arista).
Robber flies are equipped with a short, but strong proboscis which is used like a sword to pierce the integuments of their prey. The proboscis is further equipped with an orifice, distally, through which salivary secretions are injected into the prey. These secretions contain neurotoxic enzymes that paralyze and incapacitate, and proteolytic enzymes that digest animal tissue.